<human>: I've been dating my current boyfriend for 3 years, all of which have been very nice and an overall happy relationship. Within the past 2 years however, I have been struggling with my internal gender identity, before realizing that transitioning to something more inline with that of a male body and gender expression would make me very, very happy, and most likely help with most of my depression. 

However, when testing the waters, he's expressed that he would not be okay with dating someone trans, (mtf wise), which leads me to believe that he is very heterosexual. He loves his girlfriend, (me), and every part of me that makes me a girl, which at the same time, is hurting me because I know those very same things are killing me inside.

I know I love him, and that he loves me, but I know that if I were to transition we would no longer be together, most likely. (That end bit is just me hoping that he can over look this, but I know I can't force his orientation to change.)

I'm been internally struggling with how to tell him without hurting him, or at the very least, hurting him the least I can. Any ideas on how to tell him of this news would be very very helpful. I don't want to hurt him at all, but I also know that we can't stay together if I attempt to make changes to my life and body.

Give me a shortened version of the text
<bot>: I have realized that I am trans, (ftm) and I have no idea how to tell my boyfriend in a way that will hurt him the least.