how can i (F20) be less jealous of my boyfriend’s (M20) friends?

My boyfriend and I have been dating for about 1.5 years. We met on Tinder lol but before we could have an IRL date, he went to Argentina for a semester and I went back to uni. So the first four months of our relationship was through FaceTimes and virtual dates. We had some good moments, but he generally wasn’t the best boyfriend during that time (something he’s confessed to). Since the legal drinking age is only 18 in Argentina, he was able to legally drink for the first time and certainly did that. Up to three or four nights a week consisted of him going to the club/bar with his friends and no communication at all while he was out, and when he finally got home (as late as 4-5am) he’d call me absolutely hammered on the bathroom floor or something. The cherry on top was on his second to last night, when one of his friends who lived in Argentina kissed him, he kissed her back. When I found out, I was really devastated but did decide to give him one more chance. However, I can’t erase the first four months of our relationship from my memory, and it drives me crazy. When he’s with his friends, my chest tightens and I start aggressively sobbing more often than not, even though he has completely changed from last year, and doesn’t even drink anymore. I get so angry with him and jealous of his friends (even his male friends, when he himself is a straight male). Obviously this isn’t a good way to live and I wish I wasn’t like this, but I don’t know how to change it.