What school charges over $ 50,000 a year in tuition? I think there are a couple high priced ones in Boston and D.C. but that sounds ridiculous!
At any rate, residency and clinical years are a lot different from the basic sciences years. Some schools have insanely slow PBL stuff in the first and second years, and often is done to painfully torment medical student.
I personally think it is more the school/curriculum in the first two years that has you down.
If you think you are getting depressed talk to a psychiatrist, but not one associated with your medical school.
I would consider doing the two years basic sciences, take a year off to do research or something, and perhaps try to transfer to another medical school as $ 50,000 is highway robbery.
It seems many/most private schools are nearing the $50 k/year mark https://services.aamc.org/tsfreports/report.cfm?select_control=PRI&year_of_study=2014