First let me say thank you for being so open with your struggles. I'm sorry to hear you've had to struggle so much.
In regards to school, I always recommend going. A lot of people will tell you that an education does not matter as long as you have a good portfolio, but personally, I would get the degree. You learn a lot from college and not just about art. College also offers great relationships, resources, and studio time.
If it is something you are passionate about and want to pursue, then I would say not to let your age be a factor. Go for it!
Just think... 4 years from now you could be saying one of two things...
"Wow, if only I had gone through with it, I would have my degree right now..."
"Wow, I can't believe I'm about to graduate with my degree!"
As far as professional experience goes, you can always try to get side work over the summer months while taking a break for school.
Hope things work out.
Every child is an artist. The problem is how to remain an artist once we grow up.
- Pablo Picasso