Cant accept marriage our is over

[Lemoncup]

I'm finding it really hard to accept that our marriage is over. We were together 10years then 6 weeks ago he decided that his happiness was with someone else. I desperately wanted to work on things, which initially he agreed too but 2 days later he decided that he wanted to see how his feeling for her progressed. Up until 1 week ago he was telling me that I was the one he really wanted but we just couldn't be together and that he'll never find love or a connection like what we had.
They've known each other 4 months, 3 months was just at work and the past 6 weeks they've really been getting to know each other. She confessed her love 2 weeks after we split and he says he's falling for her. They're already talking about moving in together and planning they're future. Side note is they've already split 4times and don't trust each other.They go out everywhere together which angers me because I begged him for years to go out and do stuff but he didn't want to. We've discussed loads what we should have done differently and our regrets.
I know that our 1 year old and I are better off without him as there was domestic abuse and I've been wanting to end it for the past year but I cant seem to accept its over. I hate how happy he is and how he caused all of this but is getting away scot-free. I feel like I'm obsessing over his new relationship which is driving me crazy but I cant stop, I've tried. I don't want to be bitter forever. I want to accept that its over so that my journey to healing can begin which will lead to a better life for my son and I.

Any Advice?

Sorry you're going through this. He's not happy though is he? Neither is she by the sounds of it. They are so insecure they have to go everywhere together and they've already split 4 times. It sounds horrendous. He's an abusive man and the whirlwind romance is indicative of that as well. You need to try and have as little contact as possible as he will try and manipulate you so he can continue to choose between you. By the sound of it you're better off without him and you'll be glad he's done this one day although I know it's hard at first and you won't know this yet.

Perhaps do the Freedom programme and distance yourself from him. He's left you, that's really good news for you. There's no need for chats about what could have been done differently - him not being abusive and unfaithful would have been good, eh? But he was both, so work on detaching yourself from his hook now you have this golden opportunity.