I think losing people is something that almost every transperson experiences. For most of us, we're well aware of, or soon come to the realisation of, the possibility of losing people but decide that transitioning is worth losing some friends. For me, I would rather come out, be myself, and know who my true friends are, than suffer inside just to be sort-of friends with more people. We all go through the realization of how much loss we may experience, and it's totally normal to be uncomfortable with that. Most guys probably tend to focus on the parts of transitioning that are happy rather than sad, so it isn't talked about as much. It's definitely good that you're still talking to a therapist about it, as I'd suggest that if you weren't.