I would suggest you start by consulting with two professionals. First, speak with the doctor treating you for your disability. You did say you felt you would be able to physically complete medical school despite your disability, but are these hardships going to have a negative effect on your health? The third year of medical school in particular can be very physically demanding, being on your feet for surgeries lasting many hours, sleepless nights on call, and plenty of walking around the wards. I assume medical schools would make reasonable accommodations for your condition, but I think it will still be quite physically demanding. You should fully understand whether this is going to hurt your health, and particularly whether it might hurt your health in an irreversible way, before proceeding. [Not to say you couldn't still choose to go through medical school knowing it will harm your health, but hey, informed consent]
I also think you need to speak further with a lawyer specializing in disability. If you do complete medical school, will this affect your disability benefits? You don't specify whether you intend to practice as a doctor. I certainly doubt you'd be able to work as a doctor and continue to receive benefits, but even if you don't, if your disability is regularly reviewed, it is likely to be difficult to convince a judge that you could complete medical school but cannot function in a job. If you lose your disability, will you have to pay back the money you've received in benefits, in addition to your student loans? What happens if your disability later worsens and prevents you from practicing -- can you get benefits again? Then, of course, there is the financial aid issue you brought up. First, there is a not inconsiderable outlay just to make it to medical school -- MCAT fees, application fees, travel expenses for interviews, etc. Then, if you complete medical school at your local public institution, get financial aid, and do it in four years, you may be able to keep your student loans for medical school around $100k. That brings your total student loans to about $260k. That is not an uncommon level of debt for students completing medical school, but it is certainly something that would be nearly impossible to pay back without working as a physician (there are some programs to help with loan payback, but most of them are contingent upon you working as a physcian; PSLF could be a possible exception, but you'd have to ask someone more knowledgeable than I). If you have your current loans dismissed, you lower your overall debt burden, but you are likely to get some mighty unpleasant terms from private lenders (for example, my husband had several private loans for his undergrad education...one of them had an interest rate of 14%). I'm certainly not a disability lawyer or really qualified in any way to be giving advice on these matters, but I really think you need to walk through all these scenarios with a lawyer, and maybe a financial aid officer as well, before proceeding.
