Hi dmj,
Having read through your post I feel that there are a couple of things that you might like to consider.
First, therapy should be regarded as your space. This is something that should be established in the first couple of sessions. if there's something you don't want to discuss, or feel uncomfortable with, say so, and the therapist shouldn't push the issue. Even if there's something that you feel you need to discuss, but aren't ready to talk about, it can cause you more damage to push the issue than to leave it until you are ready.
Second, your experience is valid. While it is sometimes helpful to speak in generalisations, what matters most is your experience of yourself and others. Such experience, however, happens in situated instances, and is influenced by the things, people and events in the situation. When discussing a generalisation, like personal preferences, it can be helpful to turn the conversation to specific properties or qualities. Beginning a sentence with, "in my experience," can help to focus your attention on what it is that you like or dislike, or what you want more or less of.
Finally, I'd like to relate some of my own experience. In my experience I see gender as of little importance. I don't really care whether people choose to relate to me as a man, woman or something else. Rather, my experience of myself, even as a child, has been that my body and genitalia do not reflect who I am. This doesn't reflect my sexuality either - I'm romantically attracted mainly to women with a high level of intelligence and consideration for others. However, I have had very little sexual experience, and the one time I was with a woman it felt so wrong that I had to end the relationship, and haven't sought any such relationship since. I have rarely experienced romantic attraction to a man, and I often wonder whether I'm really just asexual. There's nothing wrong with that, but maybe one day, with the right person, man, woman or otherwise, I might find that the categories 'heterosexual', 'homosexual', 'bisexual' and 'asexual' are really just a fiction used to limit and control the ways we can think about ourselves. I am more than this - I am myself.
hth
Meredith