Welcome to one of the best places in the world to help you deal with one of the most awful things that can happen to someone.
I am a gay woman also- have been on this board a long time (used to post under another name) standing for my marriage a long time now- for me it was til death do us part, no ifs, ands, or buts. I don't see many gay people on here- can't say it's nice to see you here, as your heart and life are being ripped apart- but welcome anyway.
I have had many wonderful people here come to help me- a couple who I now consider dear friends (when we were allowed to connect more personally by phone, email, meetings...)
I have to read through your thread more carefully in order to dole out more specific thoughtful advice (if you want any)- but it would help if you told us more about your R- what was good about it? Her complaints about you? Did she give you a "reason" why she left?
The bottom line is, there is always hope.
I believe the best we can all do is to listen carefully to our hearts- do the right thing- they are intertwined- as my belief is that the best way to do the right thing is to listen to your heart (or God and/or angels, depending on your spirituality). And your heart knows if your marriage is worth fighting for, standing for- indeed- your heart knows if what you had with your partner was truly a marriage- that deep spiritual bond that transcends earthly dimensions. Because while I think many people call their Rs "marriage"- I fear that too many "marriages" are more like arrangements primarily to get one's own needs met (even if you are willing to give a lot in return)- which, in my opinion anyway, is not the same as true marital love- which, after the bond is formed, is unconditional. I think this is why many make vows of til death do us part, for better or for worse, in sickness and in health, but they, and most all in our current society, don't really mean it... after these noble sounding vows, very few add the disclaimers out loud: "unless you change, or you abandon me, or you fall into addiction, or you start to annoy me, or until one or both of us falls out of love"- the unspoken list is endless...although almost all believe that not only do these qualifications apply- but that to not apply them is kinda nuts. Were it not that legal marriage was not available to me until recently, I too may have fallen into a "false" marriage- our human need to connect and live with a soulmate is so strong- we convince ourselves a connection is deeper than our heart and soul knows it is. Despite the great pain of my current loss, whether or not she ever comes home, I consider myself blessed to have shared almost a decade with a soulmate that brought me great joy nearly every moment of our time together- not sure how many people are ever patient enough to find that in their lifetime. I believe true marriages are always worth standing for...indeed, your heart doesn't really have a choice.
More later- just wanted to wish you welcome and ask for more details...