found another girl in my boyfriends phone.

So I found out in December that my boyfriend had been talking to this girl he used to be friends with. It was flirting and him saying how gorgeous she is in her selfies. This had been going on since July. When I confronted him about it he went to all levels to try to make me believe it was his friend. His "friends" name changed twice in his story and a lot of things just didn't add up. I eventually found out that it was my boyfriend the whole time that was talking to this girl. He took this harder than I did believe it or not. He was so sorry and told me he did it because was lost and lonely even though I was a pretty great girlfriend to him tbh. I told him I wanted a break and needed some space from him and he just can't give it to me. He's even threatened to hurt himself because the pain he feels for hurting me is unbearable to him. As soon as one of the guys I used to talk to before my boyfriend found out we weren't together, he was interested in talking to me again and my boyfriend took that even harder. I don't know what to do because I love my boyfriend so much. I don't know if I should just put it all behind us after we have a talk about it all or if I should just make the break a permanent break up. Need advice!