Mistake I can't get over 😔

I have been seeing this boy since January, he has admitted he's liked me in the past and actually asked me out but I said no cause he lived 2 hours away from but however I know that I said cause I was scared because I've never been a relationship! At tr beginning of June I had his girlfriend pop up to telling I'm speaking to her boyf! I had no idea that they'd been with each other a month! Phones let coudnlt stop crying and it made me realise that I am actually in love with him! We had arguments and stopped talking, a week later I had his cousin pop up to me telling me how much he loves me and he has finished with her to be with me! I took him back and now we are currently together as a couple! He's coming to university near me in September but I know his family wanted him to be with the other girl but he don't want to! Although I know he wants to be with me and he has said I can't stop thinking about what his family thinks and that girl! I also keep thinking she's around him on purpose and I can't do anything or know for sure cause I'm away from him! Can anybody give me advice or anything so I can't stop thinking like this cause it has honestly made me feel extremely insecure and paranoid and I don't wanna be that gf?