boyfriend moving out....

So My boyfriend of 7 years cheated on me with someone for 2 years behind my back..I found out when I was 36 weeks pregnant, the first day of maternity leave for me. Well we weren't going to stay together, I wanted to work things out but he was in love with this girl and had his mind set. After baby was born we let our family know, but he hanged his mind right after telling them and wanted to work on our relationship. He claimed to have stopped talking to her. I found out he was still seeing her in July....we basically broke up. Since then he begged me not to leave him and claimed he'd never hurt me again, he had fallen in love when things started going wrong in our relationship and he was sorry....so I gave him another chance (I know what you're thinking, I know I'm stupid but I love him and I've known him for 10 years, best friends..) anyway...I went through his phone last night while he was sleeping. This girl had a pregnancy scare with him a week ago, and they have an appointment to sign lease papers on Nov. 25!!!! I was so angry I threw his phone right on his face when he was sleeping at 1am. (Our daughter is now 9 months old) I can't even believe he things I read in those messages....they're so in love...I obviously blew up about it but remained calm because the baby was sleeping soundly next to me....he claims he only told her that to make her feel better but that he's not really moving with her. Idk what to do! I love him so much....I just don't know what to do...