It never ceases to amaze me, how some people can blame women for all the shit that men do.
Man cheats = wife must have neglected him - her fault.
How fucked up.
My first H was like this. Guess what? He WAS happy. We had it all. Two amazing children, the big house, the nice cars, the holidays, plenty of money. I worked part time, and did all of the household chores, shopping, cooking, cleaning, the washing, all the child related things, and.....he got plenty of sex. And to boot, I was better looking than him.
He cheated anyway. With loads of women. All the time. Hit on all of my friends. Hit on my sister. Hit on my Mum. I had no idea, until one of his mates told me. I was devastated. He promised to change. He didn't though, he carried on, sometimes even in front of me, if he was drunk enough. I clung on for 4 more years hoping for change. It never came. So after 20 years together, I left him, and he was devastated and outraged (how dare I?), in equal measure.
He has had 2 serious relationships, since we divorced. Guess what? Cheated on them both.
Meanwhile, I have married DH, and let me tell you, the difference is night and day. DH is way better looking, and yet.....never hits on other women, barely seems to notice them actually.
Op - it's not you being "not enough" - it's him, because this is who he is. You could be Kylie Minogue and he'd be looking elsewhere.
See a solicitor - you are due 50% of everything, as a bare minimum. Probably more, because you sacrificed your career for him. And don't forget his PENSION. I took half of my first H pension, IN CASH before the marital home was divided up. Game changer. At least start doing the sums.
Btw, I've no idea why you have changed the password to the dating site, and then are shocked that there's no activity on his account? Surely leave the password alone, so he can go on there, make a profile yourself and message him. Let's see what he's capable of eh? Arrange to meet him, and then turn up yourself. If you don't he will just gaslight you and say that he would never have gone through with it.