Has anyone else felt like this?

I don't know how to stop feeling what I'm feeling and I feel guilty for it. so, my husband and I are about to celebrate our 1 year anniversary. We got married kinda fast, (8 months after knowing each other) This time last year 13 days before we got married I found out he cheated. he's military and while he was away he was messaging his ex telling her that she was the one he really wanted to be with and he still loved her . he never deleted the messages and when he got back I just happened to see a message from her on his phone and he basically let me read everything that was said. I balled my eyes out for days. he made it seem like he did it because while he was gone I wasn't able to talk to him much and he needed someone to talk to. with it being 13 days from the wedding and everything was already planned and paid for, I let it go. fast forward to today, I'm 7 months pregnant and he mentioned the other day that he's not being sexually satisfied....so I'm thinking, is he going to cheat again? I haven't looked through his phone in months, and I'm really scared to. should I let it go and think it's nothing ?