Collateral Damage

I am 55 years old and my unfaithful husband just turned 40. We've always had challenges in our marriage based on the age difference; he doesn't have biological children and I do (however he did adopt my youngest child). I've always feared that at some point the age difference would be a problem for him.
In December of 2019, he was up for a big promotion at work, and everyone felt confident that he would get the job. He did not, the good old boy buddy system got in the way and he was passed over. He was absolutely devastated. He is a man who always gets what he wants, he's very charismatic, lucky, and a natural leader.
While he was still reeling from that, he decided that he didn't want to be in that situation ever again and he wanted to be his own boss. He had run businesses before and decided to strike out on his own in a new field. I supported this and the drain it would make on our finances. I also work and earn good money as an Accountant. Our daughter is in college and we are paying for that as she goes, no financial aid, etc.
Two weeks after starting the new business, enter COVID-19. He was forced to try to get the business off the ground remotely, meeting in coffee shops, parks, etc. while forming his sales team. He eventually found a place to least where he could control the COVID restrictions and signed a one-year lease. He soon was able to attract an experienced sales woman from a rival business, and she brought a lot of business with her. You guessed it, she's the AP.
Each week he has Guy Night, where he and his four friends have dinner and play board games. I've always encouraged it and never given him issues over spending this time with the guys. One week I texted him because I saw a TV show announcement that he would be interested in. He didn't answer. I waited and texted again 20 minutes later, no response. I finally called because I was getting concerned. No answer. He called back and I could tell by the background noise he was in a bar, and that's something this guy group just doesn't do. He said they wanted a change. It turns out he was with her, alone, at a pool hall/bar. I believe this was the night they "connected". I found that he was on the phone with her for an hour on the way home at 10:30pm and asked him about it. He said, "I can tell you, but you're not gonna like it." And that was the beginning. He blew up at me in anger, told me I had never been enough for him and that he had always had little women on the side for texting and lunch/dinner. I'm overweight and older and I don't interest him anymore, I'm boring, etc. My world was blown apart. Everyone, myself included, was in shock because we all thought we had the perfect relationship. I asked him to leave, he moved out. I filed for divorce and we're in the process now. He moved back in a month ago to save money and I asked for one last chance to work on the marriage. He agreed. Here we are.