I am one of your subs that stumbled upon DOADB, and totally fell in love with it. I get what you're doing and I promote it whenever I get a chance. I try to promote everything I am reading actually!
^^^ I agree with this and being a reader to DOADB, I know what you intend to do with the character more or less. And maybe people on Tapastic are not the right audience for it? Who knows. One of my favorite comics most recently is about a widower who is glad that he doesn't have kids. I know, real page turner. But it is.
Everyone is offering up the same responses... some I agree with (comics are a labor of love, some are luckier than others, comparing to others, takes years, their personal take, etc).
But this is what I am going to focus on:
I know the feeling and I think what you really need is a comic buddy/support system. Do you have anyone in your life who is also passionate about comics? Passionate about making comics? Someone to geek out over stories? I've made a few friends over Tapastic that I really count on to share information about comics, merch and storytelling. I've had a blast just getting to know them personally this past year and I find that when I am depressed about my comic, or discouraged, talking to them cheers me up. I also enjoy their comics.
As far as conventions, maybe getting involved with local comic/drawing groups (or maybe starting one on your own!) can also help with table costs-- going half on a table or something. Being more involved in the indie scene somehow, getting to know local creators at your LCS might help too. There are Facebook groups for webcomic artists and indie artists that you might enjoy.
Participate on the twitter chats every Sunday, a chance to promote your work and discover comics/creators you may like.
One of the hardest things about being a creator is we want people to see and appreciate what we are creating. We want to share it and talk about it. Unfortunately, we can't control who will like our comic and when... but we can control how we promote our comic and I think getting it in front of the right people/creators/like minded people is a good first step in building an audience.
I just started getting into this web comic thing. I don't have years under my belt trying to gain an audience. There are days when I'm just tired and wondering what the heck I am doing. Am I looking at my sub count? Yeah. Do I make comparisons? Yeah. Do I get a little bewildered about some comics? Of course. But-- at the end of the day-- I really love my comic. There are good days and bad days, but I have to work on it. I have this need to tell this story and that hunger is what keeps pencil to paper despite slow growth in subs, no comments, or little interaction with readers (oh gawd a reader commented-- GIMMIE!)
Do what makes you happy-- if you're not getting what you want out of it, if it's not fun any more and you're done expressing yourself through this medium, it's okay to stop.