My bf does not trust me nor does he believe a word that i say..he is far too suspicious n thinks i cheat him..?

i truly love him but cannot stay in such an abusive realtionship..i cannot go on with him..he calls me filthy abusive names....he refuses to let me go...though all my pwords mail id n facebook id are all open to him..he still abuses and tortures me when i add a guy from college or school....what should i do?..i lost my piece of mind and i want to commit suicide...who would stay in such an abusive realtion..!!..he thinks he is right all the time and i hate him...why why cant he ever trust me ..i will give him my 100%.....my woes i m desperate to get out of this relation !!..somebody HELP !!!