Feeling so down, too much stress?

this year has been the worst. i been going all wierd and that on everyone mive attitude even more wierd immature and that than ever. people are starting to think of me as a psycho eventhough im not. im doing my gcses at school and theres so mcuh work and homeowrk i cant even do anything on my own my mind is always racing and blank and ijust cant think, i cant cope with anything it just gives me a headahce and its frustrating and at times i juz feel like cryin from it all. people walk all over me like some doormat, steal from me and just talk to me like crap, i feel like everyone hates me, and everyone thinks im a retard, i knw because people have told me. the teachers have sed they just dont understand me and they jus dno how to help me cz i make everything so diffcult. my parents have told me theyre getting fed up of me and they just think im stupid and useless. i always feel so down bored and angry im only happy when im hyper, i just feel like hurting people and destroying things. i just want to feel better about myself, ive never had much confidence, psotivie realtionships cz ive always been a loner. when the holidays was over and we had to go back to school any happiness and relaxation i ha went out the window and i just felt so scared and stressed i even thought about slittin my wrists in the night just so icould have a day off school. i dont want to die until i am very old and peeing the bed like 180 i have no intentions of ending my life but it just shows i would go to any extremes to avoid the things that are making me unhappy. i hate my shcool i hate the peopel there, i dont fit in anywhere, no understands me, no-one can control me, no-one can help me. im just a failure and noone knows how to change it all aroudn and point me in the right direction so i can be happy and stop having such a blank brain because its impossible to think and cope at all. i just wanna feel normal for once, go back to being my crazy happy self that got angry at times but always got over it and never really felt sad.