If your friends are male, and you're transitioning from male to female, the nature of your friendships will inevitably change to the point that they probably won't be genuine friendships anymore.
The old saying, "I am still the same person and will still be the same person after transition" is NOT true. That's just something that a lot of people, early in their transition, like to believe. You must realize that in changing your gender, you are also changing your role in society - and that will affect the nature of your friendships with other men. Men and women simply cannot be friends in the same way that men are friends with each other; there will always be a certain distance between them. Your male friends can already sense this coming and are distancing themselves from you (a woman) as is expected of them by societal norms.