I feel the same often. It's tough. I was about to enter my second MA. Actually, the accident happened at home the night before classes started for Fall 2011 term. It makes me furious because I was whipping around trying to find things and in a panic and THAT is how I got in this situation. Tripped over a printer and banged my head on the corner wooden edge of the bed. I had moved myself, along with my family, to another province to do that program and then the night before---bang! Done. I try not to think about it because it is what it is and I am where I am, but I do get angry. I got to keep my TA post but had to drop out of studies and then said no to a PhD as I just felt I couldn't hack it emotionally or mentally. I thought I was going to be a Prof/researcher in social studies. Now, I can't find a job as, like many many others, I can't even get an interview. Too much education and too little experience is what I hear.
My only advice to you is that YOU are YOU, You are not your symptoms, as tough as those can be. We're still here. We do have to adapt and learn and face that things have changed. We've changed. But we're not gone. And you're not alone.