hHHHHHHHhhhhh
I've been running for 3 years almost, and went through 1 reboot, and I have LESS subscribers than you xD
I say, as much as I can sympathise with your concerns of your audience being not as big as it should be, as Kurt Vonnegut once said in his 8 rules of writing fiction;
"Write to please just one person. If you open a window and make love to the world, so to speak, your story will get pneumonia."
but I'm not gonna be that guy and I'll offer my 2 cents to at least make your comic more accessible which is probably something you might want
firstly, I heavily suggest the aformentioned 8 rules of writing by Kurt Vonnegut
http://www.novelr.com/2007/11/15/kurt-vonneguts-8-rules-for-writing-fiction
and give that a read, and consider these rules to your comic, another from me personally;
your comic should be considerably easy to read, pretend that your readers has ADHD (like me) and their attention spam is only so much before they get quickly bored.
then lay your appeals down in the first chapter of your comic and show what is there to expect from the beginning!
the beginning of your comic is a make or break for whether or not someone follows you or not, and having 150 subs, I think your beginning must at least be really appealing!
another is to straight have a good connection with at least ONE reader, as stated, I do sympathise with you in regards of recognition, but ya gotta see, just me personally (and you don't have to agree with me) your focus shouldn't be on the admiration of others, you should probably be towards your own self satisfaction and getting that story out your head and onto a visual medium.
making quality work that people can enjoy? sure! that's fine!
working for self betterment? SURE!
wanting some fame and stuff and working towards recognition? that's also fine! HECK I made an entire music video with the expectation of being noticed! (which didn't work to really boost my numbers as I wanted, 5 months worth of work)
it's still gotta loop back to doing it for yourself, and maybe a few people in mind, helps your motivation be more reliant on itself than on the opinions of other people. that motive was the difference between me giving up after the music video, and me wanting to continue my comic.
fame or not fame, for me my comic is for me.
lastly, for other actual methods to product push your stuff:
community boards, discord, being interactive, yes all that stuff! and making friends and or helping people xD
same for things like interacting with people and making quality content!
and posting your comic on other platforms to cover as much ground as possible!
the problem is, people make it sound easier than it looks xD, fame is hard, it might take a decade for you, and you can't win everyone, since no matter what, you can't feasibly pander to everyone, and to add onto that, the webcomic world is also kind of small!
like 2 years is just a spec on how long it takes and the amount of work to build and audience, and sometimes you have to even pour money into it (whether it be for actual ADs or tools), and EVEN THEN this stuff takes dedication, skill and persiverence.
heck, Ava's demon crushed my soul as I'd describe it as "my webcomic but better"
the creator has worked for pixar and has been working on Ava for wayyy longer than I have for my comic, and even then, the creator has OTHER works behind them, it's a completely unfair comparison to compare a chump like me to them! and I did that comparison!
even things people like to pull up, like one punch man, one inspite his meh art, had an immense understanding of tropes and an uncanny proficiency in writing, and has even then, worked on previous works on top of that, which resulted in one punch man being a well written comic with crude art (the webcomic).
like all of these advertising tools can only get you so far, but you have to keep going inspite that, and you still outta put in that constant work to make quality stuff, which readers will glue to, you want fans? ya gotta earn it!
and even then, at the end of the day, you still have to do it for yourself... YEET
edit: to add to that, when there are oppurtunities, GRAB THEM, they are like fast moving trains that only appear once as stated by Scott McCloud's "making comics" comic book (yes thats a thing, I suggest you read it xD)