Fiancé doesn't know what he wants anymore. Advice?

So I thought my fiancé & I were super close, Bestfriends & ready to start a life together. I'm 16 wks pregnant & he's so excited about the baby.. but he just got back from a 4-5 day vacation in Texas where he & his brothers hung out. One of his brothers brought some friend girls to hang out with everyone. Well Saturday, they had a boat party & everyone got really drunk especially my fiancé or should I say ex fiancé now. Two days later he told me he had a hickey on his shoulder & he doesn't know where it came from. The same day he called me & told me he now knows where it came from, one of the girls they were all hanging out with told him that they had sex & he doesn't remember it at all! But the sad part is is that last night, I wanted to see the texts that the sent eachother just so I could see if maybe he drunk texted something to her that might jog his memory & he was really not wanting me to see. When I finally saw them, I saw that he told her that he likes her. That really broke me down bc just before he left to Texas, we were sooo close & we were great & when he was in Texas, tbh he was different. So when he first told me that they slept together, he wanted to work it out so bad, he was begging me but I told him that I didn't really trust him drinking or hanging around girls bc that situation happened. He wasn't ready to give any of that up, not even the girl that he had drunk sex with. He said that they are still friends & are cool with eachother & he just needed time to think things over. That right there told me that he doesn't know what he wants. Doesn't know if wants marriage, to be single, maybe the girl? So last night we were both crying & trying to talk things over & we kissed & almost had sex but I stopped him. He said he wanted to make love one last time, but I wasn't gonna fall into that trap. So he said give him time to make up his mind, but y'all I think I should just be done with him & only be friends with him. Advice?