I need some much needed support and advice:/

Okay, here I am 34 weeks pregnant and I found out my significant other was on POF(plenty of fish-a dating app) chatting it up with females.. he got an email on his phone that said "you have a new message from so and so on POF click here to read".. I couldn't read it because I needed his password. So I go and I create a fake profile with a few fake pictures I found online and started chatting with him. It's been 2 days and tomorrow we're supposed to "finally meet". He's super excited and can't wait.. little does he know, he's going to be meeting me; his 34week pregnant fiancé and my best friend. He mysteriously all of a sudden has to go into work tomorrow, his off day. I was told this after we "made plans" to meet tomorrow.  Idk how to handle all of this. I'm so stressed and upset, I know it's not good for the baby. I keep crying every time I look at him. He asks what's wrong and I just blame it on pregnancy hormones and being in pain. I've been extra achey lately. I just don't know what to say to him tomorrow when we meet, at the place where me and him had our first date btw. It just kills me. I need someone to talk to. I need advice. At this point I don't even want to look at him. I don't want him there when I give birth. I just want him gone. Please help!