Dearest Warren,
It's so good to see your latest post here. Your writing touches me. I do share your pain, worries, doubts, and sometimes, joys. I also wish there was a button one could push and instantly be done with it, either changing my DNA/sex/gender or society's beliefs/reactions or both. It is freaking frustrating that there isn't such a thing.
About anger and sensitivity: I don't think it's testosterone but a natural reaction to the frustrations you feel. The situation we are in isn't fair at all. It seems to me that we can consider it in the "five stages of grief" model, where Anger is #2: http://en.wikipedia.org/wiki/Kübler-Ross_model Oh boy, we still have Bargaining and Depression to look forward to before reaching Acceptance. But hey, at least we're past Denial! The model isn't perfect for sure, and I believe we wax and wane between the stages all the time. But it helps me to have some sort of reference point.
I was also feeling much the way you are the past few days. My wonderful therapist advised that I "listen to Emma," that she knows my heart. I still have my worries and hurts, but this helps me. So you, too: listen to Warren!.
As you wrote, go be yourself, a transman. Replace Kristy's clothes and presence with Warren's. Be Warren, the guy who likes to get dirty, work on his car, works out.
One piece of advice, perhaps worth 2c: don't drown Kristy. She's your heritage and will always be there for you deep down. It wasn't her fault either that you were born female. She loves you too.
Be well, Warren,
Emma