After many years of reading the literature, other people's blogs plus examining my own life, I came to the conclusion that the arousal is a symptom of dysphoria and a mismatch (whether partial or full) between gender identity and plumbing which do not align. Fantasizing as a woman while still having the equipment of a male is an odd match and a recipe for extreme confusion. However, I am not confused any longer and haven't been for the longest time.
If transition is right you will know it and it will be in spite of this arousal and not because of it. If the opposite were true you would be asking for your money back pretty quickly once your testosterone, and therefore libido, were depleted. But this is clearly not the case for the vast majority of male to female trans people.
Therefore that chapter is closed and only reopened on occasion when I see yet another imbecilic reference to this invented sexual condition known as Autogynephilia which clearly puts the cart before the horse. I suggest you search your feelings carefully and examine your past which will reveal whether you are indeed a fetishist. I personally do not know any among my trans friends but they no doubt exist. I also wish them well as I do everyone.