If you want to do art take classes in art but DO NOT go to college to learn art.  It is massively expensive and an art degree will do nothing for you.  I knew art students who were awful artists and the degree did nothing for them.  I also new people who were great artists who didn't go to college and were able to be successful doing art with just the skill they showed.

You need your portfolio (which you apparently have), and records of all your art training, exhibitions, awards, etc, along with recommendations from your art teachers. You can certainly apply, but whether you might be accepted depends on the competitiveness of the school you apply to and the credentials of the other applicants. Your art teacher might be able to advise you. If, say, you're not good enough to compete for admission at a highly prestigious art institute, you could be good enough for a university's admission to their art department. 

Apply! Apply to schools with varying reputations, requirements. Do not expect that you are a "shoo-in" anywhere. You have to compete. So try!

unless you try to get admitted, you'll never know

I would say yes, but then I'm not an expert.  I recommend you take them to someone who is qualified to judge.  I'm an amateur photographer, and many non-photographers say I should be a pro.  I can tell, however, that my work is not up to professional level.  Consequently, its best to get opinions from experts.

Yes, you're good..... go for it.....good luck.

Nice. Talented. Yes, I think so.