I feel for you, terribly. Please hear my story and my advice. I'll try to keep it short.
In the late 90's my ex-wife "figured out" she was a "homosexual." I know better know, but I was not really properly chatechized. The upshot, though, is that she refused to have relations with me and even shrank from any kind of non-sexual physical contact.
It was agony. I had no idea I could suffer that much. Not because I wasn't "getting some," as the culture would us believe, but because of the horrible wall thrown up between us.
On the advice of a priest we separated. Later, we divorced. She pursued her same sex lifestyle, and to this day lives and sleeps with a woman. I filed for and we received an annullment. Later I re-married and have a beautiful family. I'm hardly "happily ever after" because I married an unbaptized woman, but that's another story.
Here's what's important: The divorce was horribly painful for me. It solved nothing. If anything, I was the last defense against my ex-wife leaving the Church and falling into a life of what may very well be mortal sin. Although I am happier now, here's how I would deal with it now that I have reverted to Jesus and really embraced full communion with the Church.
I would not have left her. I would have accepted the agony as my cross to bear, and offer up that agony to be united to the Cross of Jesus for the cure and salvation of my ex-wife. I would pray daily before the Blessed Sacrament. I would have fought for her soul to my last breath. Maybe, just maybe, she would have rejected the garbage and filth being fed to her by her secular "counselor" and "psychologist."
Now it is too late.
SueB74, it is true that you might (as in maybe possibly) obtain an annullment under your circumstances especially given his refusal to give you what is rightfully yours (i.e., the gift of himself in marriage). However, I urge you to take a higher road and to try to do what I did not.
Your husband might need you now more than ever, even though he only inflicts pain on you and even though he so far refuses to work with you. Offer your pain to be united to Jesus' cross for your husband's salvation, and do so daily before the Blessed Sacrament. Continually pray for him. His very soul might depend on it, and by sincerely doing so you will earn merit for yourself.
I also offer you the story of Blessed Elisabeth Leseur as additional inspiration. en.wikipedia.org/wiki/Elisabeth_Leseur She never saw the results of her prayers; she went to her deathbed suffering from her husbands scorn. However, after she died he read her diary and not only converted, but became a priest.
I will pray for you. I know your pain, and I know that sometimes all you can do is desperately look for a way out. Instead, look for a way into Jesus' cross.