Hi, comeclarity; so much of your story sounded like mine. Were I you, I'd get a therapist (the school ones are fine to start with), "anyone" to start conversing with so you can work on getting some of the inside dialogue to stop in favor of outside.

I got trapped in my head until I was about 32! I went to the University of Maryland and started therapy there when I was 20 and didn't find a really good therapist until I was around 27. If I had a "do-over" :-) I'd start with working harder on talking to other people and learning to interact better, etc. Can you join a toastmasters club at school or something, take a public speaking class or join some groups that center around things you like?

I wouldn't "settle" for a personality disorder just yet :-) I eventually was treated "as if" I had GAD but my therapist and I never did really nail down a diagnosis anywhere. Your life is building the prison so you can dismantle it if you work on it now that you're getting grown and away from surroundings. But you have to work on getting out of yourself/your prison, and the only way I found to do that was another person/therapist (and my husband helped enormously after I met him when I was 34). It's hard work but I feel it can be done.