<human>: Can you condense the text into a few key points?

Things had been rocky for my boyfriend and I for a couple of months, but we were able to both get to a place where everything was perfect. The rockiness stemmed mostly from communication issues. I would express that his behavior hurt me and he would get mad at me for "accusing him" of things and it just led to argument after argument. I finally decided I couldn't change him and just decided to work around the fact that he wouldn't apologize or take my concerns seriously. Once I essentially "gave up," the relationship became perfect and he was communicating better and even apologizing when he hurt me.
The fighting lasted July - the beginning of August and by the end of August, the relationship was amazing again. While we were fighting, I messaged a guy on Facebook to be petty and get back at my boyfriend. I never thought to delete the messages and I forgot that they were there for a while. My boyfriend discovered them earlier this week and got all of my stuff out of his apartment immediately after. He pretty much dumped me without telling me he was dumping me. I understand that he was mad and doesn't owe me an explanation, but I can't believe he is throwing away two years over Facebook messages! I have caught him saying racist things about me to his friends and he has girlfriends that he sneaks off to hang out with and I always let him explain himself. It just bothers me that he won't even give me a second chance after I've given him a million chances. What I did was wrong, but I didn't physically cheat on him and our relationship was in such a good place when he found those messages.
<bot>: Boyfriend of 2 years found dumb Facebook messages with another guy, but it meant nothing to me. How do I convince him to take me back/