Relationship/bullying? help :/

I need advice, and no judgement. 
​Me and my boyfriend are both I'm college and we've been together for about a year. 
​Me and him have been arguing a lot lately. 
​Me and him broke up one night and he hooked up with a girl at a bar. The next day he didn't tell me about it and we decided to make our relationship work. 
​But right after we decided to make it work, he texted the girl he met on a bar to see her again. 
​He didn't even tell me I found out snooping through his phone
​So the other day I was on campus studying in my car (it's super quiet) and he saw my car door was unlocked he knew I didn't want to talk so he just opened the door to start arguing.
​I told him all I wanted to do was study and asked him to go away. 
​He wouldn't. 
​At this point I was still sitting in my car 
​And then his sister (who I've only met once for a few seconds) came up to my car and started yelling at me about what a terrible girlfriend I am
​I asked both of them to please go away and said all I wanted to do was study.
​They wouldn't leave me alone. 
​I finally said to his sister who was yelling at me "please move over so I can at least get out of my car."
​Her response: "no. I'm not going to let you stand."
​I started crying uncontrollably.. All I wanted to do was study.
​His sister kept yelling about how bad I am (even though she only knows my boyfriends side of everything.) 
​My boyfriend added fuel to the fire by yelling to his sister that I had an abortion (3 years ago, he didn't even know me then, my mom forced me into it, and I don't like people knowing about it.) 
​I guess he yelled about it and made it public to hurt me. 
​When they walked away I went back into my car to cry and locked my doors. 
 my boyfriend came back, he tried to open the doors again but they were locked so he banged on my window and windshield. I called my dad because I was scared and he told me to call campus police. I did. They got him to go away. 
​After he texted all of my guy friends telling them years ago I had an abortion and I'm a meth addict (which is untrue) 
​I feel so upset and can't think clearly because of all this