Trans, closeted, and in a relationship

About four months ago, I became officially "in a relationship" with my girlfriend. Simply put, I love her. She is beautiful and kind and completely unique and amazing and she loves me. But she doesn't know the real me. A few weeks ago, I realised that I was transgender. I finally understand things that have been confusing me since I was a child, things I'd repressed or rationalised, and how they all point towards my desire to be seen as a girl.

None of this changes how I feel about her. I am a gay girl after all. The problem is, she isn't. She loves the man she thinks I am. And I'm scared that she wouldn't love me as a woman, let alone be physically attracted to me. We were very gradual in moving into a physical relationship, due to her own nervousness/inexperience. Now we're just reaching a point where we're fully comfortable with each other sexually, and I fear I will ruin that by changing my presentation and to some extent my body (I'll be blunt and say that I plan to keep my penis - as long as I have the boobs and curves of a woman, I don't really give a shit what's between my legs).

I don't think I can keep this part of me secret from her much longer. Coming out to myself has heightened my dysphoria, and I feel conflicted if she calls me her boyfriend, or compliments me in a masculine way (e.g. "you look handsome"). But I couldn't imagine losing her. If she couldn't cope with my transition and broke up with me, I'd question whether it was worth it. My dysphoria is not intolerable (hell, I lived with it for 22 years and didn't even realise I was trans), it doesn't seem worth losing her on top of everything else for this.

The ironic thing is, I probably would never have realised if I wasn't with her. After a series of terrible, self-destructive romantic decisions, this is the first genuinely healthy, loving relationship I've had. It's made me calmer and more comfortable with myself. It's because of her that I have had the confidence to experiment with my presentation in private, and thus discovered that I wanted to present like that all the time.

I'll cut to the chase since I'm just gonna ramble on now. I just wanted to ask a few questions.

• Has anyone else out there been in a similar situation?
• How did your partner feel about you becoming another gender?
• If I told her, what would be the best way? How do I show her that I'm exactly the same person with the same personality, but new clothes, name, and eventually bodily changes?
• How will this affect our sex lives?
• How can I help her deal with the idea of being a heterosexual cis woman, potentially dating a lesbian trans woman? What does that mean for her identity?
• Just... help??!?