Rule number one in fantasy "scenes", is that all players understand the game and agree to the "rules". What you did was more akin to forcing a cross-dresser out of the closet, for real. I know that you meant well, and bless your understanding and supportive heart for that, but you must understand that you took control away from someone who had not agreed to give it. It might have gone differently if you had made it "safe" for your partner, by dropping clues about what you intended. Nothing to give away the delicious details, but enough to make it clear that you were going to be in control for a time. With that understanding, he might have ceded that control gratefully. As it was, and with his predisposing state, he probably felt trapped, betrayed, out of control.
So talk. Start with an abject apology about your mistake and the grief it caused. If he's any sort of decent human, he'll recognize that it was just a well-meant mistake. From there, it sounds like it's time for some sharing and understanding.
Good luck to you, my dear.
