I struggled a lot on the girlfriend issue and I posted here about it before too. As much as I felt like our relationship would never work with me feeling the need to transition, I still went ahead and came out to her after several sleepless nights, because I couldn't bear to lose her. I felt like I was stuck in a position where I had to make a choice between her or myself and it was killing me. Much to my surprise, she was totally accepting and is helping me with makeup, passing, and practicing my voice. She said she actually feels more in love with me now that I told her than before because we're communicating on a deeper level than ever. She feels like there's more of an emotional connection now. I have brought up the possible obstacles to her, for instance her being a lesbian and she says she's okay with that.
Also much to my surprise, she told me she saw the signs of this awhile ago and was expecting this conversation. That probably shocked me the most because I felt like I was always presenting as a man's man to her. She said when I was startled that I would react as a woman would. She also said that things I told her I liked (to appear more masculine) didn't really fit with the person that she knew, so there was a mismatch there. It made it very obvious that there was something I was hiding. It makes me wonder how many other people have seen these little slips over the years. Do my friends and family that I haven't told already have suspicions too?