Oh op. So sorry to read this. I know a couple who had similar issues (no baby and DH very wealthy, financially supported wife so she could choose not to work)
It’s an addiction. Often stemming from issues in childhood. During periods of high stress, these guys go almost manic watching and apparently some who were just watchers do then engage in sex, weird sex. This guy also wasn’t having sex with his wife. Sporadic at the start of their marriage/dating to nonexistent But very affectionate, hand holding, kissing, cuddling. No sex though.
In every other way, he loved his wife, attentive, spend time together doing many things. They were married for over 10 years. Something happened with the wife (minor health issue that did get resolved) and other stress issues (purposefully keeping it high level here, just know it was a lot of stress) causing him lots of anxiety, he went in to a manic session of porn and seeing an escort (for very specific weird sex). He got found out, Also by internet history. Prior to this very stressful period, he may have looked only a couple of times a year st most. Then ramped up to multiple times a day during the tough time. He very much loved his wife, he says just not in that way. In order to try to save his marriage, He went to a specialist residential treatment facility for many weeks. Came out so remorseful, with a treatment plan, apologising to anyone he ever hurt but the hurt was too much, trust had been so broken, wife divorced him. I kept thinking of how she could put up with it for 10 years - but he was very loving and attentive, supported her financially(and helped out some relatives significantly too). He’s now back to his old ways (not in a manic manner). He doesn’t see it as an issue. He is of the thought that this addiction was separate from his wife/their relationship. That his wife is in the wrong. He just doesn't get it.
So only from knowing this couple (and I did discuss high level as in didn’t go into details of his porn, just discussed the why) I don’t think he will change. I think your DP is doing it more now because he is stressed and anxious (no job, baby on way), most likely feels guilty/anxious for how much he is doing it now so in a vicious circle BUT loves you (just not sexually) and likely wants to be happy families but just does not get it that what he is doing is wrong, it’s cheating, it’s denying you the whole love a couple experience AND if he is having sex, potentially putting you at risk (likely those feelings compounded now you’re carrying his baby).
It’s not a realistic way a couple can live. He’s cheating and denying you a whole loving relationship. Will he really be able to change?? Can you live with a relationship like that?
Also, just to caveat, I didn’t read your other thread. Will go look now.