I have been diagnosed with Bipolar II (actually had to help my doctor with the diagnosis during undergrad because I was on meds, but not getting any better, and almost failed out of school). It was extremely difficult, and I still struggle with it, but it is so much better and controlled. I thought the world was ending when I had to beg my university to let me stay; I had to do this twice. I HATED trying to explain to administrators, who had no medical background, a mental illness that I didn't know much about (do they do the same with people recently diagnosed with, say, diabetes? Do they grill them and make them explain every single reason why they didn't perform well over the last semester/year? I think not.) But I fought hard. They made me change my major to something "easier" than Biology, despite me telling them that an Anthro major wouldn't help me at all with my future medical career's pre-reqs, but as soon as I got my Bio grades up, I switched back. They were for certain that I wouldn't graduate in 4 years. My last semester was hell, and it about killed me due to my heavy class load, but I graduated on time. My GPA was horrible, and that prevented me from getting into a BSN program the first year after graduation, but I took more pre-reqs so I could apply to more programs in the area, and I am now in my third week of a BSN program and doing very well.
I was born for this. My illness may have set me back a year, but I'm only 23. Plus, it has taught me SO much about medicine, the public's reactions/misconceptions about illnesses, life in general... that it will be a huge help when I am practicing medicine. It will help me be a better nurse. Maybe not on all days... it sucks to feel crappy for no good reason yet have to function like everyone else... but even then, it will be a reminder of what most of my patients are going through.
All of my professors know about my diagnosis, and they haven't said a thing about me not being able to be licensed. However, I've never been suicidal, admitted for Tx, etc. -- don't know if that makes a difference or not as far as the law goes.
Sorry this entry is so long. I just want to encourage you. Be strong, be tenacious, and know that so many successful people, from nurses to actresses to writers to prime ministers, have or have had mental disorders. Don't be shy about seeking all the help you can. I know how hard it is when no one, including friends, professors, or a boy/girlfriend, seems to understand you. There might be resources close by you that could help, even if it's a nurse who has gone through similar difficulties. Best of luck to you!