Sounds like you have a good wife so don't blow it over a fantasy. Unless you are transsexual and need to change gender and live fulltime as a female (huge life changer!) then do not mess up a good marriage over this. You will regret it.
If you are truly a TS then it's different but what you described sounds like most of us - run of the mill hetero CD who wants some space to express and feel free. But don't destroy a good marriage in the process.
