i cant believe i feel this way

ok so and ex girlfriend of mine, has decided she wants to be a he, and he is undergoing his transformation, im totally supportive, i still love him very very much, i don't really have a problem with the man part, it did take me a little while to get the pronouns in my head. but and this is what makes me so awful, he has started to refer to himself as a gay man, i don't know why this fills me with such awful tellings, but when we met he referred to himself as a femme lesbian, he never was femme, but he was still a lesbian. i guess this is what you would fell if a man told you all the sudden he wanted to date men, well i guess. i don't understand, i understand the whole i want to be a man part, he isn't the first girlfriend to tell me that, but, he was deathly afraid of penis's when we were together and long before that, so how do you go from wanting to through up t the sight of a penis, to wanting to sleep with people who have one? i will forever support him, in what ever he wants with his life, but i guess im felling like i never mattered or something, like i didn't count, which is awful because i was so crazy over her. i haven't seen him, so i don't know if the same butterflies would be there. but i just don't understand, and i cant realy say this to anyone, even my wife, or sister. dam the whole need to be politically correct.