Two part answer here.
One, if I were to ignore the fact that I love my wife and love my relationship status, if it were just me, I would have transitioned 20 to 30 years ago. I could turn the light switch now for myself at any time.
The other answer is reality. I do love my wife and she says she loves me, and I am as afraid of losing her if I transition as I am afraid of death. Maybe I am less afraid of death. However I do cherish her and want to care for her and love her forever, and hope to be loved by her as much. What is gradual is the slow build of rejecting self denial and forcing my core inner being from being expressed. I cry silently to myself as I smile lovingly at my wife every time I see her. I do love her deeply and unconditionally. I hope she feels the same about me. What is gradual is that I am about to burst, to explode, unless I take the woman in me and let her shine. I do not need gender therapy for myself now. For myself I would transition instantly. I need gender therapy to lead to couples or marriage therapy to help my wife see how miserable I am.