My relationship is in a crisis

My fiancee and I have been having issues. Anytime we get into some argument about something he brings up past events for example a person I had intercourse with before I was with him an he says hurtful things an call me names. Everytime he gets mad he starts digging in my past and it's getting worse he somehow is able to find old messages from yrs ago that I may have texted a friend or message on facebook. I permanently deleted my Facebook so I don't know how he continues to find messages. These messages are like from yrs ago not even recent and he thinks just because I had conversations with a guy friend he thinks I'm having sex with him. I have friends I went to school with I'm not doing anything wrong. He says that I'm gonna end up being with another guy and he knows all of who I had sex with because he digget in my past and was pretending to be me on Facebook talking with alot of the male friends from school. He sends me images of what messages and everything. I need advice. How is he able to do this and why bring up past things that is irrelevent? I feel alot of resentment.

I believe I have suffered enough from it. Unfortunately I have to do what I got to do for the sake of me being happy an my sanity. I told him he has serious issues and if he doesn't stop I'm leaving for good. If this happens one more time I'm done I can't keep feeling this way an him trying to make me feel guilty somehow it's annoying and VERY immature.

I'm sure Mr Far Too Into You (Thus Insecure) is *perfectly* aware of how pointless and immature it is to dig out or mention these (I'm betting) screenshots that he kept from back when your FB profile was active, or to start throwing insults and counter-accusations. That's not his point. This is: 'This'll shut you up and get you right off the topic of your latest issue with me'. Got it? You're obviously 'getting' him overly on the defensive via how you approach him to discuss a problem re an inadequacy or failing on his part, sounding too accusatory and too end-of-tether in your 'opening speech' (e.g. 'I can't live like this!' and 'I need a man that X, not Y!'). So, fearing entering a discussion about it will lead to the worst (getting dumped), Mr Panicky starts a fire in the hope that the smoke will get in your eyes and up your nose and distract you from your protest speech. Feeling the 'ping' yet?