And that is perfectly reasonable. This is a change for you, and a possibility that you probably hadn't considered at all. It takes time to get used to anything new.
With time, you and your husband will develop ways to articulate both sides of his being. Mimi and I find it convenient to simply use the appropriate names to designate the side of me that we're talking about. I'm a single being, and I do not consider my femme personality to be distinct from my male self, but it is very convenient to say "Eryn will be going to that event" rather than stumble over others way of saying it.
It is also natural for your husband to be uncomfortable. He has told you something that is potentially explosive. He doesn't know what his revelation will do to your relationship but he has taken the risk because he has faith in you. Your husband wants the best for the both of you. It is very likely that, if you keep communications open, your life and your husband's life will be richer for the experience.
Take baby steps, get used to each other, but keep talking to each other. Both of you will need to be willing to show a little forgiveness at times. It can be difficult, but the more you discuss it the quicker you will become comfortable with the situation. That's when the real enjoyment begins!