Since my W had an A with a woman, too, I'll share some thoughts and some of my experience.
First, you're not alone. There aren't a lot of us here whose WSes had a same-sex A, but there are a few. There's a thread in ICR, but it's not very active. Still, you might find it useful.
Second, I've been on SI for over 2 years, and my sense is that an A is essentially the same trauma no matter what gender the ap is. My struggles seem to be pretty much like most other BSes' struggles, and the words other BSes find helpful are the words I tend to find helpful.
R for me required the same stuff everybody else seems to need: NC, willingness to answer any and all questions I had without TT (trickle truth - the FAQs section has most of the acronyms you'll see here), transparency (W keeps me informed of whereabouts and companions at all times), IC, MC. My own special requirement - that W court me - turns out to be not so special - lots of BSes want to be courted by their WSes, for pretty much the same reason I do.
My W committed to R on D-Day, but I held back - I didn't want to say 'Yes' to R until I knew I could say 'No', too. And I didn't want to commit myself to more potential pain unless I saw my W was willing to make the changes necessary to become a great partner.
One of the earliest issues I raised was whether she was willing to commit to monogamy with me and whether she was gay or bi (the obvious answer - bi - is the one we're working with).
The big questions you need to answer, IMO, are what do you want and what does your W want. If your answers are aligned positively, and if you have or adopt the same vision for your M, R is possible. If you've got different visions, R sounds pretty iffy.
I was a wreck for several months after D-Day; most BSes here report something similar. If this had hit when I was a road warrior, I don't know how I would have coped.... Note: IMO, the quickest way through this crap is to feel your feelings. The worst way is to stuff 'em. What are you doing with your feelings?
What's your W doing to change the thoughts and feelings that allowed her to cheat? IMO, a WS needs IC - they just have to much garbage built up to be able to change without help from outside.
At 28+ months out, our M isn't as good (i.e. pleasurable) overall as it was before W's A, but some of it is definitely better. The pain of the A is still a sticking point. But we're both committed to making our M great, and that means we're a lot happier together than apart. I continue to believe that R is the best choice for us, and I see almost weekly posts here from people who are happy they R'ed.
So some people heal and R. Alas, there's no single road through this hell, and there's no single formula for getting through it - but rest assured you can heal and thrive.