Really need advice PLEASE READ

How do I get a guy to leave me alone I tried off putting him he keeps texting me we hung out once and I just wanted to hangout and he knows I have a boyfriend because I told him and he was fully aware and when we hung out he kissed me and stuff which I didn’t like ... and I was kinda scared because he was my only way home and I couldn’t call anyone or have anyone pick me up from my house because no one was home and he is kinda scary . And he pulled off my sweater without my permission which wasn’t cool at all .. I did not approve and then after that sex .. happened for like 3 mins .. and now he won’t leave me alone and idk I just want him to leave me alone because I don’t want him to tell my boyfriend about something like that to harm my relationship .