Guiltydreamer, you’re on a sad path by your own admission. You also admit to feeling guilt and your very nick name affirms it. You even go as far as calling it pathetic. Why would you encourage Dean, the OP, to follow the same route?
Dean, keep in mind how much of a fantasy this all is. It’s not worth destroying your relationship if it works. Be open with your partner. You don’t have to throw everything in her face: just start talking to her gradually about your feelings, be patient and take a year if you need. Exchange with her on desire, on sexuality, on the complexity of desire. Talk to her about transsexuals in a general fashion. Open doors for her first. I’m telling you: in all probability, you will be surprised…