In both of the long term relationships I've had before my current one, we had lots of intimacy issues. I never wanted to be undressed, never wanted to be touched, etc. It was the elephant in the room, always. But I had really good girlfriends who never wanted me to feel uncomfortable, so it was never made a big deal of. Maybe if it had been, I would've transitioned sooner. Who knows.
When I decided I was ready to transition (roughly 8 years after realizing I was trans), I initially decided that I didn't want to date anyone until top surgery was over and done with. I felt like it would only be fair that way, knowing how much I disliked my body at that point. But I met someone online and we really hit it off. They were there when I started T, drove me to/from top surgery, and around for a lot of my important milestones. But they were also an idiot, so we aren't together anymore.
My current girlfriend is someone I've known for years, so she's seen all the bad times and the good ones. I wasn't planning to date for a while since I have some pretty heavy medical stuff coming up this year, but the heart wants what it wants. I feel a lot better now with T and top surgery, so most of the intimacy issues that were present before are gone. She's totally supportive of whatever bottom surgery route I'll end up going down, and I imagine things will only improve from here.
I had a lot of success meeting people to talk to/befriend/date using submission blogs on Tumblr. That is probably what I would go back to if I found myself suddenly single, but I don't see that happening.