Alright, if it's okay, I'm gonna give you a bit of tough love. If you don't want to hear any of this, by all means completely skip my reply.
To ease you into it, yeah, I'm gonna relate to you a little bit. Comics are so, so hard to make a living in. And it's really easy to feel like you're "stuck" when doing them. If comics aren't your thing, then by all means - it's a minority in the art world for a reason, because it takes so much work for so little return (at least for indie creators starting from the bottom).
Fine arts are hard enough as it is, making a living in comics specifically is even tougher. You need to come up with a ton of different sources of outcome to keep it profitable - merchandise, ad revenue, Patreon/donating, Kickstarters, convention sales, etc. And even then, 99% of comic artists still have a full-time/part-time job to keep food on the table and a roof over their heads.
So if you feel comics aren't for you, that's fine. Lots of people have left this medium for the very reasons that I listed above. You really need to love drawing comics to want to do it every single day for possibly no return.
Here's where some tough love comes in.
This:
I'm thinking maybe the indie comics I write don't fit into the pretentious, existential, minimalist comics thats in style right now either.
Is not fair. You can hate on other comics, successful or unsuccessful all you want, but you can't blame them for your lack of success. Many of these artists have come from nowhere, just like yourself, and have had to work for years - YEARS - to get to where they are (and even more artists have been working the same amount and are STILL waiting for their moment). Yeah, styles come and go, and some comics get SUPER popular in a short amount of time because of these styles (I'd be a hypocrite if I said it didn't piss me off, because it really does sometimes), but you can't blame these trends and comics who have found their stride because of them as a reason for your lack of success.
Finally, I'm gonna talk about your work, Diary of a Douchebag specifically because it's the one you linked and compared to other works. Critiques might not be what you're looking for though, so again, skip if need be, but I feel like if you do read this, it's what you really need to hear.
Diary of a Douchebag, from my first impression of the first handful of pages, is a self-indulgent comic about some guy who thinks he's top shit and talks like one of those obnoxious bully characters from those old 80's/90's movies. You know the kind. We don't like these characters for a reason. These end up being the characters we want to see lose, we want to see karma inflicted upon. I get if the comic is supposed to be his journey to self realization and how he changes as a person, but I couldn't even make it past the first handful of pages because it was just actively trying to hit every single douchebag trait on the list. People are "lame", school is "lame", everything's just "lame". I have to say, I have never met an actual college person who is actually like this (the only people I have met who are like this are people on 4chan who do it ironically because hurhur autistic edgelord humor hurhur)
Now don't get me wrong, my own main character from Time Gate is a Grade-A bitch. She committed murder when she was still practically in daycare. So yeah, I love a good, hard-to-love character as much as the next guy. But in the first few pages, you still have to give your readers some reason to care, and if it takes forever - FOREVER - to get to that (if at all, this is assuming your character does undergo any sort of change) then there's no point in pressing forward and hoping.
Hell, the one character I can relate to in DoaD is the random black guy who's being initiated into the frat. He gets up, says "This is dumb", and walks out.... and it's just the greatest thing ever. And it's also the only thing I can relate to while reading this - to the harshest point that I just want to stand up, say "This is dumb" and walk away from reading this. That is the most asshole point I will make here.
And it seems like a lot of your comics are like this. Depressing, self-indulgent streams of consciousness. I think the only one that I could tolerate was the short story you did (the future tense one), but it was still repetitive based on how it was structured, and it still followed the same "life is depressing and I'm an asshole" storyline.
Moving back to one of my earlier points, yeah, you can sneer at the "pretentious, existential, minimalist comics" but you're pretty much doing the same thing, just with different traits (and this is arguably harder to read because why would I want to read a comic that's more depressing than real life.)
Paired with the art and it's just . . . hard to read. You can do a realistic looking comic, but it takes a lot of practice to make a realistic comic that's also expressive and appealing. So a lot of your art can be improved as well.
Overall, I think my major point is, don't blame the success of other comics when you've still got so much left to work on yourself.
alright i'm done, thank you lol
TL ; DR: If comics aren't your thing, that's okay, it's not for everyone. But don't blame the success of other comics for your own setbacks, and don't use it as an excuse to not try and improve yourself. You can carry this into your work as an art teacher or an illustrator/painter, and it doesn't just apply to comics alone.