Judy,
Your wife really is putting you in a difficult situation now, to me she is saying in different words that it's either your crossdressing or your marriage. I do understand where she's coming from but she's not giving you the chance to explain your CDing needs.
If like most of us you were born like it and will end your days with it, nothing is going to change that, OK you have the slight confusion of being gender fluid , where you have ebb and flow. To cut that need off completely and to try meet her demands isn't going to work if you are totally honest with yourself.
You need to forget the stash of clothes, ( don't purge !) they are irrelevant,it doesn't matter if you have one dress or a thousand , you have to come to terms with your needs even if it does take counselling and then put your wife in the picture, if you still love one another strong enough then hopefully you can resolve the problem.
I found once the word separation had been used and mutually agreed to the sensible talking starts , the important issues are put on the table and the true values realised. We came to a compromise which at the moment is working, but for me stepping out the door as a CDer was part of the deal in return I gave my wife a husband and a father for the children.