My husband 💔 what am I supposed to do ..

So me and my husband are every traditional.. well maybe me more .. I've always been taught divorce was never an option you just work things out , I believe porn is like cheating , and if you talk to other women sexual is cheating to me. I'm almost 37 weeks pregnant and I found a snap chat conversation from Nov my husband had with an ex saying how he had missed her , the sex him and Wanting to hang out (he says he doesn't even remember that conversation). Telling her we don't really do anything anymore (that's because sex hurts me when we do this is since about 6 months pregnant). This is not the first time I've caught him twice with porn and twice talking to ex girlfriends it's only been a year and I dont know what to do anymore....I feel so alone...