Hi! I know, I know, long time, no see. Between the birth of my son, and GPF leaving Keenspot, I just don't participate on any forums anymore, no time. But! I do still read BtB, and I've got to agree with what people here are saying. Ian, it's certainly not lack of cartooning skills! Your artistic skills are top-notch! Just because a webcomic is "successful"(and in this instance I am using success as "able to support the artist full-time") doesn't mean it's got the best art. I mean, frankly, look at User Friendly. The art is no great shakes. Sluggy is better, but certainly not "best", and what about XKCD? Fer cryin' out loud, it's stick figures, with incredibly awesome writing! I used to think it took incredible art skills to be successful as a webcartoonist. And then I thought, no, it must be great writing. And then I went with "charisma of the artist/ability to promote one's work". And now I think I know the true secret, why some webcartoonists have made it big, and some have languished. As in most things in this world, it takes some skill, some determination, and a big heapin' helping of pure dumb luck.
If you feel you need to slow down on BtB or whatever, then do what you need to do to recharge your batteries. But under no circumstances are you allowed to say that you are not good at cartooning. You are one of the best. I'm sorry success hasn't found you yet, I wish it would find more truly talented, gifted people, in all fields of life. Sometimes, that's just the way it goes. But I do know this. Success in cartooning will never find you if you quit. There are tons of people out there who honed their craft for years and years, unnoticed, before one day they became on "Overnight Success". But it can't happen if you don't continue, persist, even when you don't want to, especially when it's tough and unrewarding. And I can't guarantee that one day you will definitely be a success. But I can guarantee that if you just quit, you never will be. And you'll always wonder about what could have been.
So, take some time. Get yourself re-focused. Figure out what you love to do, and what you suck at, and try to improve the suck-at skills, and find a way to make what you do every day focus more on what you love. If you want to try something totally new, try it. Go in a completely different direction. The great thing about webcomics is, it's so free. You are not stuck to 3 panels, 3 days a week, or anything. Do one big panel! Do 20 small panels in succession. Do a comic a day. Do one comic a month. Add animation, or sound, or whatever you want. I just encourage you to do something, and stretch yourself in new ways. The best part about being on the downswing of readership or "success" is, there is only up-side! You can be crazy and inventive, and what risk is there? What is there to lose? Nothing! You can only learn about yourself, your abilities, what works, what doesn't, and improve. Make it fun again. Now there's a better measure of success than pageviews, someone who does something that they absolutely love doing, and it is a joy to them, every single day. I would bet by this point, you "love" doing Bruno, but on a regular, daily basis when you start to think "OK, so I gotta get a comic up by Monday. What should I have Bruno do this week?" there are times when you get discouraged, or bored, or just tired, and want to do anything else.
Some interesting exercises I've seen other webcartoonists doing, to stretch their skills and keep them energized and feeling motivated. One picks a different artist every month, and starts up a sketchbook where they try to emulate their drawing style, downright copy it, just as an exercise in drawing things differently than they usually would. One is drawing a girl a day. She likes this certain art style, so every day she draws a sketch of a girl in that style. I know of one guy who wanted to work on caricatures, so he started randomly pulling up pictures out of Flickr, and does a quick caricature of them, limiting himself to like 20 minutes. Anyway, those are just some examples. The idea is, try and pinpoint something you want to improve, and then task yourself with doing something every day, to work on that skill. But, I think the key is, draw something every day. It doesn't matter if it's a quick Fiona sketch in the corner of a work-related document when you're supposed to be listening to a meeting, or doodling when you're on a phone call. Or drawing the people around you at lunchtime. Just, try something new, is my advice.
Big hugs, and hopes that it gets better soon.