I read your post about 5 times and still had no idea where to begin. You are packing around one hell of a lot of stress. You didn't say if you are a single mom or not, but if you are, the stress and exhaustion of that is more than most women can handle, but also attending nursing school, which is grueling, is asking for trouble..........if YOU don't ask for some help.
You absolutely must get over your inhibition of talking to your doctor about things. They can't help you get well if they don't know you're unwell.
I would urge you to see your PCP for a very thorough work up, head to toe. There are a lot of things that need to be ruled out. I would also suggest you obtain an evaluation from a psychiatrist. Again, it's just my opinion, but I think you've got some anxiety, anger and self-esteem issues that once dealt with would make you a much happier, healthier person, mother and eventually, RN. I think that's what COULD be "wrong" with you. And I believe that therapy would make you feel normal/human again.
You have a really great life ahead of you if you finish nursing school, but if you let these problems wear you down, your chances of dropping out increase and that would be a real waste.
Peace
Greenlydia