Not just his life ruined

Hiya it’s been a while since I posted here. I won’t bore you with the details but my story is like so many ppl.. my partner of 21 years has been gambling on and off for the whole time although things didn’t get really out of control until around 3/4 years ago when he started lying a lot more! He never really contributed to the household and wasn’t the best dad to our boys growing up ..in 2021 it came out he had been cheating on me and the gambling was also out of control. I ended it but we eventually got back together after his heartfelt promises of him saying he wanted to marry me and have holidays as we’ve missed out on so much over the years … he continued to lie and had a secret phone but in jan 2022 he started to put things in place to stop and really started to try … ga..counselling and cbt …he even tried hypnosis. However he has slipped up 4/5 times during the last year or so and now doesn’t bother with ga and although he still has blocks on stuff there’s nothing ongoing in place to help him. This is something I really struggle with as I was petrified of him maybe relapsing and he promised me he wasn’t and didn’t want to be that person anymore. But this weekend he’s just went mad ( his anxiety and anger absolutely needs addressing but his excuse is well I’m better than I used to be!)and ended the relationship for good . He says I just nag nag nag at him and he never wanted to marry me ever and all thru the last year he has been just grinning and bearing it! I am angry and heartbroken that I put so much work into saving us and he has done the bear minimum just to keep me off his back. He doesn’t seem to realise he’s screwed up my life too with his addiction and I’m in constant fight or flight mode. I feel so stupid that I’ve wasted yet more time trying to make it work. He minimises the cheating to others even the counsellors and tells them .. she finished with me so I went and met someone else!! I did finish him because he lied about gambling again but he freely admits to me that he was on dating sites for a year before this and had been chatting daily with the woman for 3 months before they met when we were trying to work it out or I was !!  I’m so so broken and I’m finding the whole thing so very harrowing. He also won’t move out and adding to my heartbreak.. I’ve just found a lump in my breast and his reaction was … oh I’m sorry to hear that!! I honestly don’t think he is human!! Help me?