Should I leave or stay...

i cry everyday.. its always on my mind. not a day goes by were i dont think about what happened. every relationship iv ever been in , i was the one who was cheated on. im currently together with my bf of a yr and about 3 months. wer in love. he kissed another girl at his friends 18th bday party while playing a drinking game and they were apparently drunk. but the thing us , is that they kept it from me and she had a bf . he read her diarie read what happened and a week later i found out about what happened , which is when her bf read it. they were all friends before i came along. my bf and this girl always txted even after me and him got together i got mad alot . after i found out we have trust issues she keeps trying to see and talk to him, he has cryed and says hes sorry and he blocked her number. what bugs me is the fact that they acted as is nothing even happened and didnt tell me and they werent going to. i told him before he went to that party if he cheats hes done. i think i was stupid but i gave him a second chance. before the party i felt like i was number 2 compared to er . almost all his time was about her n her bf cuz they were all friends.. his X even tried to say i dont belong in the picture and trying to get me to leave. we still fight sometimes whenever shes brought up in convo or appears in the same place as us. i just dont know what to do and im so depressed and its driving me crazy..... someone help me please. i dont know how to feel or act or do... i love him and i want to marry him but if i have to live in fear that oneday she will steal him from me again then i just dont know..

leave him, don't marry him. If he did that after a year and three months he's not committed to you. trust is very important.

oh no no no he did that at like 4 months but still after a yr and three i just cant let it go and it bugs me and it hurts me and i just dont know what to do..

you shouldnt live in fear or have to leave him, if a person loved you he would never have done that

i know and i have thought about what to and what not to do a lot but im not sure. we have soooo many good days then sometimes we fight a lot and thats normal but i just feel like we arnt going to work. idk if i should just end it or keep going..

you need to weigh ur pros n cons