You'll hear opinions on both sides on that subject. Some will tell you that the formal schooling will help you a lot because it focuses your study on the right areas (assuming you go to a good school), others will tell you it's all about intense, daily practice, which school merely forces upon you. My own perception is that there are a lot more people who lament going to expensive art schools as compared to people who say it was worthwhile, but that's not necessarily a representative sample nor indicative of very much.

All I can suggest is to consider it very carefully. One really never knows where the jobs are going to be anyway; a lot of formerly "safe" fields have changed pretty drastically, and even a lot of the professional and technical disciplines are becoming full of freelancers.

And there's no rush to decide. Just do your homework and look around at all your options. I'm sure you'll find something that makes you happy!

I may be biased, but if you do go to college, DON'T go into Fine Art, go into Illustration (many times put under the umbrella term of 'design').

I think school helped me very, very much, but a lot of it is knowing what's good for you and being able to be around teachers who will pull no punches. You can practice ad nauseum and still never 'get' certain things the way teachers can explain them. And why reinvent the wheel?

Note that there are lots of online classes, Massive Black sells DVDs that are pretty instructional and neat, but before even doing that, you will need a lot of basics like figure, color theory, and so on. Like building blocks. Anyway, the main advantage of school has been being around many other learning artists and varied teachers. I wouldn't go to school TO GET A JOB, that really never works out well anymore. Go to school OR take individual classes if you think you'll learn better by getting that constant feedback, assignments/prompts, and so on. Artists tend to learn in many varied ways... there's also the program that  darc is taking online now, a sort of mail-in-for-crit thing, and the name is escaping me, but yeah.

Out of curiousity, why would you recommend illustration as opposed to fine art?

From my experience in illustration and graphic arts thus far, I think I have basics of figures, colour theory, and so on. I'd forgotten about Massive Black. Might be worth looking into!

Illustration teaches technique, CONCEPTUAL skills, composition, etc, much better than any fine arts program I've taken. I would definitely recommend taking a painting class or three, but Illustration doesn't just cover basics, it has the best prompts, creative teachers, and think-out-of-the-box approach.

What you do IS illustration, looking at your gallery, so unless you want to be more of a fine artist, I don't think a fine arts approach will help you as much as delving more into what you already know. Illustration majors is a wide range of knowledge, because it's not restricted to a single medium like, say, painting. ie, you can be an illustrator and a 3D fabric artist, because illustration is very much about storytelling in a piece and that's almost harder to pick up than the technical side.

Going to college for art will surely whip you into shape! If I could afford to go back, I would.

Good luck with whatever you decide to do. I'd offer advice but I'm stuck at a fork myself right now.

If there is a continuing education program, you might be able to pick and choose different courses in different departments that will help you hone your skills without having to burden yourself with grades or department requirements, and would probably end up being cheaper overall.

Would you be stupid to not try?