Dresses don't make women crazy... Men make women crazy.
Since I will certainly pray for you two, I will pray that you reach a happy understanding sooner rather than later.
It's not, of course, the crossdressing that is the real issue; it's the trust that's been challenged. Can she trust you? Yes... She can trust you have always been a crossdresser and always will be. Does it matter that you didn't tell her? Yes. Does it matter so much that you crossdress? No, probably not.
My second wife, may she rest in peace, would sometimes smoke - cigars. She made a spectacle of herself when she smoked too... Rolling the cigar like an oil baron, puffing like a train, and, usually telling loud dirty jokes when she went that far...
Did I love her any less because she didn't tell me she sometimes smoked? Yes. Did I love her a lot less? No. It was just something she did because she was who she was. You take the whole person when you marry them, whether you know it or not. It's not your job to judge them, but to love them and help them along in life.
Crossdressing, like smoking, is not in most marriage vows. Love, understanding, and forgiveness, however, are always there - because that's what a marriage is and has to be. I pray it won't be long before you both start laughing again:
"You wear skirts and dresses? Oh, you silly man. Let me show you how it's done so you don't get a note from teacher..."