<human>: This is a bit long. So 5 years into the relationship my girlfriend went to Costa Rica where within a week had kissed/made out with a man she met. She comes back and breaks up stating guilt; so I fight to win her back because I accept partial blame (she didn't blame me for any of it) because I was in a rut and barely left my house nor did anything to contribute to the relationship. 

We make it work through some miracle but I clearly have trust issues from there on out. I clean up my act but admittedly I never fully let my guard down. Fast forward 2 years. My girlfriend has been great.  100 percent in the relationship and never any concerns of another man; not that I believed her. She makes a new group of friends through a volunteer program and I notice she is particularly nice to one and it sets off my insecurity. I go thru her phone and check up on her and find nothing.  But the trust is gone and she calls it a week ago ,after I threaten to leave. I again panic and beg her to stay and just last night I found that after a week apart she watched a movie with mentioned friend and made out with him. She thinks we can't repair the damage and that she is no longer interested and I managed to get her to reluctantly try again with new trust established. 

Is this a wise choice?  Do people come back from this twice? Am I abusive?  Is she abusive? I love her to death and would do anything I can to help her and she's proven that she would too. I just want to hear if it's something we need to break from or if this is possible with effort

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: we both did somethings wrong but I seem to be the only one still interested in trying to make it work.