Questions: Break Up & Divorce

One day I saw an emoji next to this girl's name on y boyfriends snaphat. I'm not the type to just search through his phonebut I saw it because it was blatant. I asked him about the situation and he said he hasn't message her since January andhe didn't know how the emoji got by her name. So I kept asking him did he messaged her and he kept denying it then finally he sarcastically said yeah I messaged her since that's what you want to hear and he kept this "lie" up for 10 minutes and he finally said he was just telling me what I wanted to hear. we discussed it in let it go he promised me that he was not talking to another girl. 3 days later he's on snap chat and I look at his phone and I was curious so I grab his phone is white and looked at his messages with herjust to be sure. All of a sudden I scrolled up and found all of these messages between him and the girl he supposedly did not message since January. He asked her if she wanted it (Sex) and meeting up so he could spend the night with her. He was telling her his hours at work and she even said herself that if you have a good girl don't mess it up with her you seem like a good guy. He completely disregarded what she said & was still trying to meet up. This occurred during a time when we were not having sex regularly because I recently got saved. He said it was a weak moment for him because he wasn't sure why we weren't having sex and he was not happy about it. He was very remorseful, crying, praying, and really trying to earn my trust back but I'm not sure because I have zero trust for him now and I don't want to put us through hell trying to regain my trust for him. I really love him but I'm just heartbroken about it. What should I do?