I am sorry to hear what you are dealing with.
I know you're probably still in shock and are hurting. My opinions may not help you feel any better, I'm afraid. Gently, IMO, there's just not much in what you've written that points to optimism for your marriage. You've been basically tossed aside. I'm sure it was a huge shock to learn that she is either bi or gay, but that's secondary to what she has done to you.
In other words, separate from learning at she isn't clear on her sexuality, she's treated you like shit.
--No remorse.
--I love you, but I'm not in love with you. (Total bullshit. She's trying to say, I love you, but you're in my way. I want to exercise my selfishness without regard for our marriage. I want to play with my sexuality, indulge myself at your expense.)
--Rewriting marital history (...been unhappy for a long time. Did she care to share that with you? Is adultery an acceptable way to solve unhappiness in a marriage? It's total bullshit.)
--Blame shifting (again, it's total bullshit. Don't accept any of it. Her affair is 100% on her. That was her selfish, dishonorable choice. All marriages have issues. That isn't a free pass to an affair.)
--she was quick to move out.
Whether she is straight, bi or gay, she has just thrown your ass completely under the bus. Is that how she treats someone she "loves"? Lying, betraying, falsely blaming, discarding?
She didn't say she wants a trial separation from her AP, in favor of giving your marriage a second look, so to speak.
Getting your mind around all of this is so hard. How could it be? That's something I still don't understand.
I have visited a MC and she seems to think that hope is not all lost, its possible WS could suddenly realize that the grass isn't always greener.. but its hard to believe that you known someone so well for 10 years to have it all flipped completely upside down in a day.
Yes. This is true. But, the question becomes not what will SHE realize, but what will you realize.
So, what to do? If you're not already meeting with a professional therapist (IC - individual counselor, as they are referred to on this site) I hope you will do that ASAP. Find someone who has a lot of experience with infidelity. Hopefully you can find someone who can provide some help sorting out this mess. Also, keep posting here, if you find it helpful. This place is a tremendous source of hard-earned experience in the nightmare of infidelity.
You did nothing wrong, my friend. Nothing. Strength to you.