I think you've already hit the nail right on the head, there. He absolutely must be focused on something else for it to be an engaging story any audience would want to read. Especially since it sounds like he is already post-transition for the most part?
So that can't be the driving conflict of the story. Rather, as he attempts to fulfill his goals in life, being trans (or more specifically, society's treatment of him because of it) is one of the major obstacles in that conflict, not the goal itself.
In other words, if being trans is the defining aspect of your protagonist, you're going to have a very limited audience. That can be a much more powerful, and approachable, plot device if it's a secondary characteristic. As in, he's a would-be singer, who just so happens to be trans, and by God, he'll be a singer no matter WHAT the world throws at him. So he's much more focused on his life in general than just the one aspect of it.
Maybe it doesn't sound like much, but it's a huge distinction that early in the writing process. Does that make sense?