I have problems in my relationship

So pretty much what happened is that I came back home from my birthday dinner my boyfriend was watching a boxing match on that day by the way this is a long-distance relationship I live in California he lives in New York and we've been together for a year and 4 months I've been very paranoid I'm not mentally stable and I have said things to him that made him feel unsafe but let me get into the point so he posed the boxing event at all that he was watching on his computer I thought he was going to watch it alone but then when I heard who was talking in the background by the way this was on Discord I heard a girl and I didn't know this girl and then I asked who it was and he said his female friend but he invited the whole group chat me and myself I've been cheated on in the past either with my boyfriend they cheated on me with their friends or just some random girl from their school and right now it's really Rocky and I don't want to lose him I want to prove that I can improve myself if anyone has suggestions I'll take anything I just don't want to start over with someone else