I am absolutely devastated....
That's normal at this point. You're probably in shock. That will pass soon, though it never passes soon enough. Some advice and random thoughts....
1) You're probably on an emotional roller coaster. When I was there, I activated what I called 'an observer' to watch me go through the ups and downs and keep me aware that I was under no physical threat. My observer also helped me relax about time - I calmed down and kept telling myself that healing will take as long as it will take.
I recommend creating and observer-type for yourself - and it that terminology doesn't work for you, what will?
2) I'm really sorry your H thought it was OK to explore his sexuality after marrying you. One thing that concerned me was whether my W was bi or gay. If she liked sex with me, R was possible if other requirements were met; if she was gay, R was impossible for me, since I didn't want celibacy. So if R is something you want to consider, make sure your H knows who he wants to be with.
3) Do not try to control your outcome - both D & R can be honorable and healthy resolutions to infidelity. Figure out what you want from a partner. Once you know that, figure out if your H is willing and able to provide it. If you think you want to be with him for the rest of your life, identify measurable requirements for R and see if he'll agree to meet them. If he will, R is, in fact, possible.
If you decide you don't want him, D. If you want him but think he won't deliver what you want, D.
Don't push yourself for a fast decision. You're making decisions that will, hopefully, affect decades of your life and your kids' lives. At this point, have faith in yourself to come to a decision soon enough.
4) I found that the gender of my W's ap was not a big factor. My W betrayed me. It didn't matter with whom. (It probably would have mattered if she had cheated with someone close to me.) I found myself going through essentially the same struggles virtually every other BS had to deal with.
I'm pretty permissive, though - if you have major objections to same-gender sex, your approach will probably differ from mine. You are free to - and need to - find your own way through this. You can read things that others have done to recover by reading threads on SI, but you have to find out what works for you. Just have some faith in yourself.
5) IMO, the most important thing you can do for yourself and kids is to heal - to process the mass of anger, grief, fear, and shame out of your body. You may not be aware of all those feelings yet, but wait a bit - they'll come. They'll seem overwhelming, but remember: you have feelings; they don't have you.
Also, your H cheated for his own reasons not because of any lack in you or your relationship. Your H failed; you didn't.
R requires 3 healings: BS heals BS; WS heals WS; together they heal/build/rebuild the M - if both want to do that.
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If you've got questions or concerns, let us know.