How would you react?

Ok so this 2 years ago but my cousin brought up again & its making me think stupid😳 . anyways. So 2 years ago i was baby sitting a military lady daughter & her friends daughter. My phone was dead. When i charged it& it turned back on i had no texts from my fiance but only from my cousin telling me to call her. Right when i was about to call her, she called me. She told me that if i could baby sit her son (My nephew) i told her she didnt have to ask just drop him off & that she should already know ill say yes. Still no calls text or anything from my fiance. His sister told me he was drunk & passed out. Ok this where it begins. I came home in the morning to wait for my nephew. So she said she wanted to sleep over i said ok. Then she told me "Your bf is ratchet. (This was before we got engaged)" i said "dude seriously? I didnt do shit to you why you calling him a ratchet?" she said "Because he kept calling my phone , texting me saying he wanted to "talk" i told him i wouldnt ever do that to my little cousin." i said "Nah dawg you lyin" then she showed me the messages & phone calls. I texted him "fr ' you pretended you was asleep? & i was up all night worried about you! But comes to find out ! You tried to talk to my cousin? You fucking serious! I wouldnt ever do that to you & you say you LOVE me ! But yet you trying to TALK to my cousin you fuxking kidding me we fxkn done!" i ignored his calls & he was texting me "Babe i didnt try talk to her. Please answer ill slit my throat i promise i will. " took me a day to talk to him again or my cousin i was pisst. But then we made up & stuffs the day after. So tonight she came in my room & reminded me about that night & she told me how he would cheat on me & that he still tried talking to her. But he told me he didnt. I try believing him but he has a bad rep on talking to other girls. He kick me cause i told him i kinda believe my cousin but kinda not because she has a bad rep of lying to much to get attention. So he kick me in the face. I told him i wanted to leave he called me a stupid fat bitch &stupid slut that no one would love me like he does....... Im lost cause its true i love him. But im tired of being abused in every other way 😞& idk why i stayed with him. I feel something that makes me feel good. He was there for me before we became as a bf & gf. I was pregnant from rape & he was there. Always there. I loved & care for him so much of how much afflection he gave me but these year being together theres a happy days but most days bad days. Idk how to go im stuck