Depression and stress. Become useless.

Help me.i am take much stress on every single thing. I have developed a phobia within me of everything. It is continuously increasing, I remain in fear most of the time.for eg. I have to wakeup early in morning to attend class which make difficult for me to sleep and I spend whole night in thinking what will happen if I won't get up my class will be ruined. It has destroyed my academic progress and results. Once I got so panicked that I forgot how to write in exam which ended up in getting less marks . I am 21 and has lost hair like hell from sides may be because of tension. I afraid to walk freely in the class it makes me nervous as everyone is staring at me. Please help anybody otherwise it will be killing me more and more and one day I will become useless.