Me(F) and my boyfriend (I'll call him M/we are a straight couple) and I have been dating long distance for 6 months. I'd say our relationship has been healthy besides normal concerns and arguments. I would have put money down they he would never talk to another girl but he has.

Some context to the situation; I guess we are both jealous partners but he worries whenever I have guy friends. I understand his concerns and have always reassured him. I have told him every time I believe someone has flirted with me and every time I met someone new. This time was no different.

I met a guy (I'll call him A) who seemed nice to we started talking(in a friendly way). I told M about him(A) as I usually do and off the bat he seemed okay. A few days later he(M) said he felt like we were going to break up(to his friends) and lied to me about actually saying it. He finally admitted saying it. He had concerns he was going to loose me which I understand but I reassured him and things seemed to be okay.

A few days down the road he kept saying he didn't trust me and wanted my account information which I was hesitant to do but finally gave it to him temporarily to try and relieve his stress. He obviously found nothing there but it hurt that he didn't trust me. With how jealous he was becoming and with how strange he seemed to be acting (to the point where things didn't feel the same with us) I asked him for a break to try to gather what was happening. He took it really well and that made me glad.

A few hours later he told me that he had been talking to another girl while we were dating.) I saw what he said to her and I suppose it wasn't too bad but it still genuinely really hurts and makes me feel like if it can start off small then it can lead to more. He called her pretty(and her name), told her he liked when she answered fast, that he liked when she was checking out his account, calling her eyes beautiful, listened to a playlist he was supposed to listen to me with, told her he was going to come visit her and drink and smoke with her, told her private info about me(including private conversation screenshots,) etc. The girl (W) called him cute(as well as his name), tried getting him to leave me, talked trash about me, said she waits all day to talk to him, etc.

After this happened I am extremely hurt and reluctant to go off of break with him(keep in mind this happened while we were dating.) I've tried talking to him since but I just can't and nothing is the same. I feel as if I forgive him it would take months but I truly liked him and I don't want it to be over. What should I do?