Double ditto, hell, quadruple ditto everything Esposa wrote. Been there, done that, own the damn t-shirt shop and branded the logo.
And I hate to qualify this, because I do not want you to think we are diminishing your pain - we are not! - but there's a difference between being with someone for over a decade with marriage, property, time, etc, and being with someone for two years with a extreme infidelity and emotional abuse.
A common question you will find in this forum is asking ourselves or others what we would do differently. Given the choice, and knowing what I know now, I would not have continued my romantic relationship with my H, I would not have married him, but I would have tried to remain as good a friend as possible providing emotional support as long as he would have let me. Now? There's too much invested on many many levels to simply just walk away.
I got sucked into the vortex with my H, and like Esposa, it destroyed me. I'm still recovering. Going down the rabbit hole with your partner helps no one. It doesn't help you help him. Only he can do that for himself. The best thing you can do is pull yourself out of the hole/vortex/madness and take care of YOU.
Best of luck to you. Please take care.