There's been some mention here of D being easier than R... Part of me can see that. I imagine it's extraordinarily difficult and painful to build anew a relationship with someone who has just eviscerated and given me the deepest emotional shock and trauma I'll ever know.
But marriage is usually more than about two people--it's overwhelmingly about a family, too. While the two direct people involved "may" find that they recover faster with a clean break D (trust me, though, it's damn hard, too)--THE FAMILY IS SHATTERED.
A nuclear FAMILY is important to kids at any age, IMO. My father ran off for a string of other women when I was 18 (oldest of four kids) and us "kids" each struggled with it for DECADES. IMO, marriage is a ROCK that can give kids an anchor to withstand the vicissitudes and adversities life hands us--even after we're "adults."
I'm not advocating, W, that you R or D, or that you stay together for the family. Just sayin' that it's ALL hard.
I know you don't feel like you're doing well, but you are. I was too traumatized to act decisively. Indeed, I can see now that my XWW's infidelity and subsequent departure triggered "abandonment" issues in me that went back to my FOO (up to and including my father's departure). Ironic, isn't it, that my father's departure in part led to my own fear that if stood up for myself and maybe alienated others, they'd leave me? I know now that that very fear contributed to that very thing happening to me! More irony.
And now I can look back and see that what happened was supposed to happen. I needed to learn that lesson so I could finally heal a big part of me that needed it. It took me being abandoned in the most traumatic way possible, to get me there. Irony, in spades.
Which leads me to my final thought... No matter the final outcome here for you, you're going to be okay. I know people diminish such thoughts here sometimes, especially when the shock is omnipresent... But if you choose that no matter what happens you will make the most of it, then you have great gifts coming to you.
Pain is just pain. It's when we try to avoid it and choose false comforts, that we get into trouble, IMO. We can brace ourselves and steel our resolve to ensure we're never going to be "victimized" again, but that always leads to a hard and rigid stance--and the pain does not go away.
Someone in this thread encouraged you to let the pain "pass through" you. Another variation of that is to accept and surrender that you are in pain; that it's okay. It just is. Buddha said that we will each experience 10,000 joys and 10,000 sorrows in our lifetimes.
Surrendering to and accepting that emotional pain is part of life, gives us a chance to relax, breath and be grateful for all we do have. I am humbler, more loving and more compassionate person now than before. With the passage of time, too (almost three years out), a deeper joy is peeking through; a happiness grounded in my soul via the toughest of trials. Those are wonderful gifts.
You have gifts coming your way, too, no matter your choice of R or D.
Blessings, LA