I think Im going mad, Help?

I dont see any of my friends much, at school i dont talk if i dont have to, I get so depressed I feel like ending everything. Ive been self harming for years but ive never felt this bad. My boyfriends the only one I want to see but i only see him on weekends and im scared hes going off me, Some girl wrote on his wall today and i had a panic attack, crying & hyperventilating. I cant sleep usually, I just dont see anything to look forward to, im ok at school but ive got no dreams or plans ... I spend ages on facebook looking at these girls im so desperate to look like, then try really hard to but i never look as good . When someone annoys me i just snap & lash out, i get dizzy and dont know what m saying.. What should i do ? Am i going mad?