I can do the taking feedback thing, but having confidence is a whole different jar that's never gonna be filled. I have severe self esteem issues and don't really like anything I create even if others like it 
Still, I wanna make things and get better so I keep at it
And that's the actual problem that keeps you away from success. If you don't love yourself and your own work, it will never get better. Let me tell you I was through a lot of shit in my life and I also very often felt like my work is not good enough. But in the end, you should make art because you like it, it's something you want to do. If you don't like it, why do it? Maybe you should try first fiure out things and brings you joy and want to work on it. When you look at famous artists, you can see they love what they do, that's the real key to success. So don't think about gaining a following, but figure out, what you want to draw and makes YOU personally happy. Then you can expand.
I’m just here to support everything @Lunar-Turtle said.
You need to show your pride and show what you like to do and stay positive.
I’m no artist and if you look up my Blue Life comic you will see that.
But I’m not giving up and I have worked my way up and only try to be a good friend who helps others.
My suggestion for you is to try again. Make something new and perhaps do it together with someone.
Read other comics and see what works and not.
Not just in art but in story.
Making fan art may not be necessary if you can do art and other posts around a specific interest or community. For example, people who make original furry art, original illustrations of diverse characters not often represented in media (like say... black characters, south Asian characters, characters with disabilities or older characters as examples), LGBTQIA+, or even just relating to a specific hobby, like say illustrations based around rock climbing or original tabletop RPG characters etc.
I have a lot of friends who have found success through making work about one of their interests or areas of knowledge or experience outside of art, whether it's illustrations that show a historically accurate reconstruction of viking clothing, comics explaining the autism spectrum, or cute drawings of leopard geckos.
The other thing I'd advise is to reach out to other people on your level, give them encouragement and grow with them. It's a good way to make lifelong friends!
This sorta thing is a really good way to go about it. There's floofyfluff on twitter who's most known for the kawaii sharks but does all sorts of adorable animals and great illustrations. I got a reasonable amount of notice for my LGBT+ frogs sticker collection after a con (wow cons feel like forever ago don't they) because I think frogs are cute and apparently so did lots of others. Finding a niche can be a really good way of introducing people to your art.
unfortunately the one thing you can't do, despite your best efforts, is make people care about your work. what you can do though, is show your passion for your work! love your own content the loudest, and people will see that, and think "hey, maybe this is worth checking out".
because like @Lunar-Turtle said above, no one wants to hear people put themselves down. if you don't like the work you're putting out right now, that's valid and fine. but you also don't have to say it out loud 
Work on your art first, work on your reach when you're proud of your art.
There's no need to expose yourself on the internet if you don't feel confident yet.
I think I can give you an advice on art, not really on how to draw better, but how to create better. You see, I noticed over the years that artists look at their own art with different view than other people. We like our art, because it was made in our minds, but what if you imagine you never saw it before and never heard of it. Try to look at your art as total stranger and ask yourself: Would I want to read this thing? Would I like what I see? When you do this, it gives you a different perspective and you start to see your work in different light, many times it helps to identify what's wrong with it.
If you want to attract people, create somethign they want to be part of. For example, I created my world with mindset that it should feel welcoming The art should look nice, colorful and there are many things for people to discover. I wanted them to feel like: WOW, I would like to make a character and walk around in that world, because there is so much to explore.
Now, can you imagine doing that with your comic and art? Is there soemthing that attracts people and makes them curious? Try to think this way and remember when you became a fan of somethign that already exists, like tv show, game, comics, anything. Something made you a fan and that something keeps you there. I think this is soemthing that is very important for comic making, because it gives people reason to engage and be interested in your work. Remember, you create art not only for yourself, but also other people.
My 2¢ are an audience doesn't come before some sort of established narrative for a comic unless your art attracts people in itself. Most people only grow a larger audience after years of posting regularly because they like and are driven to create out of love for the medium. I was posting on tapas for 3 years before I passed 250 subs, and found my niche.
This can be tricky so I'm just going to share what I personally did. I definitely have a niche (alien invasion/cyberpunk + dystopia all in manga style) which I refuse to give up. Writing and drawing these kinds of stories is what makes me happy. 
Over the years I've found that people who are really interested in my work tend to also be interested in gothic things, horror, paranormal, series with heavy world building, etc. So, I market myself using those tags. (ie "gothic manga" "alien world" "world building" etc.) I also have a schedule for my novel (once a month) and a schedule for new art/videos (tri-weekly for art/once a week for videos).
I've found that having a schedule, marketing myself, and not giving up what makes me feel passionate has helped me garner an actual readerbase.
I would definitely recommend trying more social media than you listed in your original post! A lot of people hate on twitter and instagram, but honestly I've found so many artists from those platforms.
Sadly, fanart is a huge way to get found, but I've also noticed hashtags and "memes" are a GREAT way to find new artists as well. Always jump on the latest fad like #DrawThisInYourStyle or #MeetTheArtist or #CartoonMe or literally any art meme that makes its rounds!
And just as others said, it's going to take years. No one builds a community in a week. You have to enjoy it, not just want it. 
To build on this (the post above) , social media is a super good way to get found, use hashtag for example when I update (#webcomic and variations of it) and join communities, on twitter I'm on a list of webcomic artists, I'm also in some discord groups and have a discord for my own comic.
And try to reach out and communicate with the readers you already have, offer a Q&A, draw an inside joke for your comic. I recently made stickers for a milestone celebration so readers can have something cool to put on their laptops if they like the comic... You know... Just create and communicate
I have no right to give advice on this, but if you want to grow a following based on OC's, here's some stuff that I've seen working for others:
1) A unique and consistent art style will help people recognize and find you even if they don't know who your characters are. Stylized art that fits into specific aesthetics, rather than generic art that doesn't say anything in particular, is the way to go.
2) Use your OC's and build narratives around them. Draw mini comics, or art that features them interacting and emoting. If you give them a clear personality/hobbies/interests, there's a higher chance that viewers will connect with them (and beg for more~).
3) MEME. You know how every once in a while an art meme goes around, like the 'strawberry dress'? If you come across one you like, put your OC's in it; make them participate! It's the next best thing to drawing fan art~
Although I don't have that big of a following, I noticed that I receive more attention when doing current art challenges/contests. What happens is people look up the recent entries, like a bunch of them, see yours, and then check out your gallery if they like what they see.
Because of that, I have more likes on my dtiys posts than my original stuff. And the original content I have that's gotten a ton of likes were a part of OC_Tober.
As for fan art, I don't think just drawing recognizable characters is really enough. You'll have to take into consideration relevance and popularity. Like a new anime that's popular now or a well known tv show that's hit an anniversary milestone. But I'd only do it if I like said property which it'd make it feel less like homework.
And like @DokiDokiTsuna said, definitely jump on those memes. Unfortunately they're random and can pop up whenever. I wish I did the strawberry dress while it was still a thing.
, it's probably time to rethink what you want to get out of art/comics.