This is what I get out of this, feel free to correct me. H is a crossdresser, like most of us he doesn't want to be but was born this way. He is not going to quit. It seems that his desire is escalating ...it does for most of us.
You have known for quite a while, I think I read 3 or 4 years?
You do not accept it at all and quite probably never will.
H has probably lived with this for most of his life and undoubtedly has felt all alone in this and is quite likely ashamed of it as well. He desparately needs someone who understands him, I do not think you will. His bahaviour sounds a bit rude or pushy to demand you accept it but he is desparate.
Sounds like a mexican standoff to me. He will not quit and you will not accept it. Either he gives in and goes back to keeping it secret from you or you tolerate it and allow resentment to build up and the relationship suffers. I do not think either one of these sounds good. I wish I could offer something but there is nothing I can offer.
No DM you do not know me. I have been married twice and I did not allow either of my spouses to even have an inkling I do this. It has always been there from as far back as I remember. I didn't want to cause my spouses the same level of discomfort I had about this. It is a burden I bear alone. It is a lonely existance, I am sure he is frustrated too. I wish both of you the best.