Hello, Pedal, and welcome to Susan's. I'm fairly new to the site myself however I can attest to the fact that this is an amazing place filled with people from all walks of life with an abundant amount of experience. I'm incredibly happy to see that you have joined us here and are obtaining helpful perspectives here already.

I am a straight FTM who recently began transition; I'm on my third week on testosterone. I am fortunate to be on this journey with an amazingly supportive partner who has been by my side for the past six and a half years. Although I have just recently begun transition, this has not been the start of my journey. Like your partner, I too went through my own journey of self-discovery. Something that is so incredibly profound and personal that not many people can truly understand unless they have walked this path as well. However, it appears that you are doing everything you could with your love, support, encouragement and patience. Although I cannot speak for everyone, for me, my partner's support has been a blessing.
But the journey is not easy for either party. Although us guys do have our personal paths to travel, you as a partner have your very own path to thread. When my girlfriend and I first met I identified as stone butch... extremely stone. Which meant I had very rigid rules and boundaries when it came to physical contact and intimacy. Our sex life was good and very pleasurable, however the more I began to look inside the less our intimacy became in terms of physical intimacy. My sex drive plummeted, severely. Sex simply was not something that was on my mind and it had absolutely nothing to do with her or my attraction to her. She is an incredibly beautiful woman whom I've always desired. But like your partner tells you, it wasn't her - it was me. But although she was(is) incredibly understanding, it is still something that I knew was incredibly difficult on her. I think it may simply be human nature to feel that sense of loneliness, rejection, etc. We as human beings crave intimacy and having a lack of is going to undoubtedly effect us. I know that it was a very difficult blow for her because our attraction for one another is intense, always has been. But there was a point where there was no sexual intimacy for over six months at a time.
If you are interested I will ask her if she would mind me sharing her email with you and you could talk over this with her as well if you'd like to get her perspective since it seems you are now in the place she was.

I like the suggestion that some people have made about maybe discussing the possibility of making out and sharing that form of intimacy without it going "all the way" because it may set him at ease. I know that when my girlfriend would get close and I got the sense that she wanted "more" it did make me uncomfortable which turned to guilt. It wasn't an easy journey to go through by any means but like you and your partner, it wasn't a matter of lack of love but simply due to my own personal struggle and growth.
If this is indeed the same situation then from my experience I would like to offer you one word of advice: hang in there. The more comfortable I became in my masculinity and gender identity, the more I was able to then turn to my comfort in my sexuality. First I had to accept myself for the man inside and try to somehow become comfortable with my body and it's parts. Although this part is different for every guy, for me it was about coming to terms with my body as a sexual vessel. We tend to genderize sexual organs but I came to a point where I was able to not see certain parts as female parts but simply sexual organs. And I began to grow more comfortable with my body and the sex picked up.
And... one more thing to keep in mind... if he does go through with transition and begin HRT then rest assured this will likely change. The first week after my initial injection things were normal in regards to my sex drive. My sex drive has never been something I called high or even 'normal' if there is such a term that can be applied to this. But this past week the hormones have certainly kicked in. My sex drive is through the roof and my selfless, considerate girlfriend has been kind enough to be there for me (chuckles). Even if it has meant two, or three, times a day. We were actually just joking about the fact that she is going to bed and looking forward to work tomorrow because she needs a break, lol.
So hang in there, Pedal. I respect you so very much for your dedication and obvious love you have for your partner. It is so very commendable. From a guy who has gone through this journey and is still going down a foreign path, you are doing everything right.
When my partner would bring up the topic we were able to talk about it openly. Maybe bringing it up to him with these ideas won't be such a bad idea, the biggest thing for me was to know that it wasn't her expressing unhappiness, unfulfilled needs or disappointment towards me. Because those things were always on the back of my mind, that feeling of guilt because I did feel bad that I could not meet those needs. However she was so incredibly understanding and reassured me that she understood. I was able to see it as the facts, that there was simply a physical need. And we talked about it when she needed to, we listened to each other and got through it step by step, day by day.
I hope this helps some.
- Nico