Confused about my relationship help asap before i make the wrong choice.?

i have been in a relationship already gunna be a year this saturday. i know i should be happy really happy but i ain't i dk were ur relationship is at. i think we started off to early we bearly had about two weeks together and i got pregnanct then i had a miscarrage that made your relationship stronger but later on i got pregnanct again around that time we broke up cause of some girl then we end back together then we broke up for two days doing them two days he was talking to some other girl i found out by his myspace n i saw that the other girl had pictutes of them kissing i end up lossing my baby and end back with him. doing the first pregnancy he was supporting me then the second time he told me that i had to abort it if want to be with him cause he had a carerr in front of him. he couldnt support me and the baby then a month in a half later i end up preg again with twins i end up losing my twins but doing that pregnancy he was so happy always holding my stomach but he always will tell me as much as it hurt we couldnt support them not now to abort them. i had 3 miscarrages now we have like two months and i havnt end up pregnanct but i have hate for him i dk why. when im with him im super happy and he makes me so happy im the first girl he has taken serious and has been with for this long. but i have hate on him for being with a other girl while we werent together he has told me million times he is sorry about everthing cried to me but i cant let it go sometimes.I have broke up with him sever times this week and he crys to me that he know he has mess up and cant be without me help i broke up with him 4 times already this two weeks i dk wha i want but i do love him from the bottom of my heart and i cant be without him what should i do.