I've had serious problems since 14, as well. I'm 50 now and have had at least a dozen jobs, multiple hospitalizations, SSDI 1993-96, SSDI 2004-present. Thank God there is SSDI and a father who supports me. I watch all of the money I spend and my income is less than $24K/year. I rarely buy clothes, I don't use my car a great deal, I just try taking care of myself, I've learned to budget.
Mental health treatment documentation is most definitely used for SSDI consideration. And after applying for SSDI you are given a psych evaluation (from an independent psychologist) and that evaluation is used in court. My health records were about 6" thick and the Judge commented on its volume (and the fact that he couldn't read my psychiatrists handwriting). You have nothing to lose applying for SSDI and the psych evaluation is not heavy scrutiny - the psychologist just documents what you tell them regarding issues, functioning, work history, etc. and doesn't make any judgements.