"Nervous juvenile, won't smile, what became of you..."

At the moment I'm going through a little blip, too many thoughts and worries are over-loading my head and making me close to shut down. The only respite being thoughts of suicide.
It seems like a recent return with a lot of feedback, on an assignment has left me both confused, upset and angry. 
It has also left me wondering if I can even complete this course with any sort of reasonable grade. It doesn't bear thinking about as I've really put all my proverbial eggs into one cliche laden basket so if this doesn't work I don't know what I can do or even try next.
It seems like my ability to cope or to take on any sort of criticism, be it constructive or very destructive is getting smaller and smaller. That isn't good where feedback is of, if not essential, to the things I like and am involved in. 

Why can't I cope anymore? 

The person who did a parachute jump, went on stage, could mix with a variety of people from different backgrounds in a room and who could handle a roomful of people and make them laugh with it; little man, what now little man?