I'm so sorry.
But oh my god don't marry him!!!!!
You have your head screwed on.
I will say this... prostitute use is calculated. It's not a drunken accident (not that that's excusable!)
It's not the fun and excitement of discovering a colleagues fancies you (again, not acceptable!)
It is a cold hard decision that cheating is fine. You did nothing "wrong" - and if there had been issues, anyway he should have come to you. His actions were long term and repeated. So what stops him doing it again? When that urge takes him? Love, guilt, fear of getting caught... none of that stopped him before, so why would it now? What is he going to do to stop it? Because just saying he will won't stop him. Either it's a compulsion or he just didn't give a shit before. Neither of those reasons will mean he'll change his behaviour. There is something wrong with him, and "I nearly lost you I won't do it again" simply is meaningless. You can't trust him AT ALL. Bare minimum, I'd want to be there when he has it all out with a counsellor to find out why he let himself do it before. This is what he did during the good times love - what about when there are hard times?
To be honest, the pathetic and violent smashing of the laptop (evidence)
is red flag enough to leave him!
Have you actually been shown his adultwork account by the way? I'd want to see that, not just the payments.
I'll finally share my experience. My XH used AW - including buying sex. Turns out, he'd done it for years before he met me. I didn't know that til after. When I found it, I had all the "don't know why I did, I'm a fool, I'll do anything" crap. Like a fool, I just about believed the "I only looked" bullshit. Married him. But he carried on. I found out again. Divorced him. He doesn't know that I know his AW password.
Guess what? Within 6 weeks of meeting his next girlfriend (you know, the honeymoon period) he was paying for sex again.
I know you are going to hope that yours if different.
But what's more likely? That it was some random lapse that he can walk away from, or that there is something wrong with him?
He will do it again.
There is some need in him that you don't meet. And that's not your fault. You give him everything (FWIW I was 'better' at sex than my XH, I was open, willing, adventurous. But if they're after 'illicit', you can't give that.
Walk away.