Sharing Our Innermost Thoughts

I am in a relationship where we fight a lot. Okay most of the times i start the fight just because of her best friend. She told me at startung days of our relationship that it’s just her best friend nothing else. But recently i found some chats of them talking about how the sex was which they had last year(we werent in relationship at tht time). And she explained everything that they are still in relationship and she’ll end this very soon. I melted on her innocency. And after some days she actually ended the relationship and i just told her not to tell the guy that u are datung me.and they are going on as friends. No doubt she actually loves me a lot. But it stikl get hurts whenever i found her talking to him. And i always fught with her about him. But i regret later. Idk how it’s gonna be. But it’s very complicated for me