Here's a link to the Davidson database list of articles of articles about psychological issues in profoundly gifted asolescents, including succesfully completed suicide, existential depression, and articles from James Webb who wrote the popular book, "The misdiagnosis and dual diagnosis" guide book.
http://www.davidsongifted.org/db/browse_articles_188.aspxI have read here that people seek the services of gifted specialist psychiatrists like Dr. Amand because psychological problems have different needs in gifted than non-gifted people. I've seen him talked about for little kids who have ADHD plus high giftedness. I can't tell if that's only for learning disorders or all other problems, or if his services extend past school aged kids.
http://www.amendpsych.com/I don't know if this is helpful, but at your age if you're not doing anything else you could go to the college and take psycology classes and learn all about it. The college students are likely to be gifted and the professor moreso. You can learn as much as you can there as anywhere else. Maybe you'll learn something nobody else learned yet about 2e (which they call twice exceptional-having two labels, giftedness plus something else.) You'll be finding answers and be less alone. I think twenty-one's too old for job corp and you may not want to join the army to get a scholarship, but there are pell grants to help you and I think they help pay for your books if you ask the college counselor. It's worth asking about.
