How to forget my boyfriend's suicide attempt?

My boyfriend is on a Anti-Depresent Pill. He hasnt been on it but maybe going on 2 weeks now. Well when he first started it he was with me at my house. He was getting really mad. & I had promised him I will always take care of him. he was breathing hard & scaring me. he told me too leave him alone & I didnt he got really mad but then he went into like a ceaser or sumthing. & then he came out of it & didnt remember anything that has happend. Well Friday night; this past friday he had took too many he was only suppose to take Half of one & start taking a whole on Saturday. He took 3 whole ones. & He went crazy on me. He told me too leave him alone once again. But I cldnt stand seeing him lay there & hurt & be in pain. he threatend too kill me if I didnt leave him alone. my parents was gone. it was only me & him here. I took off into the kitchen cause I was so scared an I was bout to go check on him then he came around the corner bent my back on the Stove. & Started reaching for the knives ; I started to run out side but he got too me too fast so I ran to my room & locked the door. & I got in my closet & called my friend to calm me down cause I didnt think my boyfriend wld hurt me the way he talks about People Abusing women. He has went to jail for Attempting to kill his step dad for abusing his mom & almost went to jail for beating a guy with a pool stick cause he had punched that guys girlfriend. well I got out the closet opend my room door & he was standing there with a Butcher Knife. He sat on the floor an tried to slit his throat. Finally I didnt care what happend too me I didnt want anything to happen to him I went to him grabed his hands & layed him on the bed. about 5minutes later he went into that Coma thing again. & then he was fine. He was like How long we been asleep; & He had no idea what happend. I told him & he started crying. im just really scared this may happen again but I dont think he would hurt me. & I really don’t want too break up with him. what can I do too try & help me forget it? ; I can’t go to counsiling cause my mom wld kill him if she knew.