I suspect the feelings of Gender Dysphoria coming and going in intensity is the normal, not the exception. You are 39 now and have been living in a “Life Style” predominately based on male type expectations. Hopefully you were successful in your employment and education during your adult years. Hopefully you developed survival skills to get to where you are, as everyone does or fails (even cis-people). At 39 years old you are an early 80’s baby; you grew up in an anti-trans world, so you had to learn to survived.
I am 68 and retired. I have had many short and long periods of time when my powerful desire to be a “girl” would slip into a: lets say a closet (actually a good analogy). These were ALWAYS times of intense involvement of the other very real elements of who I am / was. I was the Commander of Veterinary Services for Operation Joint Guard in Bosnia in 97′. Months and months of intense activity with attention demands that required the soldier in me to take over, so the “girl desire” gently waited. My command didn’t require me to be a male or a female; it did require all my attention.
I am a veteran of 4 different military actions since 1970, and this was a common response to the intense moments of those deployments. Same thing happened while working on my dissertation during my PhD program, and again during medical school. Not all the time, but during those time of the need to focus on the “other pieces of me” to step up and perform.
I found that as my career developed and I earned / could afford more and more leisure time, my desire to be a girl came roaring back. Even as a practicing veterinarian I would sometimes throw myself into some professional program and become so involved that the “desire” slipped back into the closet for a while. I couldn’t walk around wanting to be a girl all the time. I had to want to be a soldier; male or female. I had to want to be a veterinarian; which requires 4 years of student hell. I had to want to be a good surgeon, a good hospital organizer, a good boss, etc. I spent the last 33 years trying to be a good husband.
I sincerely believe that my “girl” greatly influenced how I approached all of these jobs. So, not all of my “girl” was in the closet; just that part that wanted to sing out and dance a “Happy-Girl-Dance”. I believe I was more sensitive then most of my fellow male friends. It was fairly often I was told that I was the best boss some people ever had; a direct result of my “girl” shining through my male role.
There were also times when I forcibly shoved my “girl” into the closet. During the 70’s and 80’s when being transgender was almost unheard of by most of society I would have runs of powerful desire that were phenomenally stressful. I remember lying in bed and self-mutilating myself where my vagina should have been. I couldn’t keep doing that; I had to develop survival techniques to save me from my “girl” screaming to get out.
So, when you are calm, at peace with yourself, and envision your immediate and distant future: do you wish you were a man or a woman in that future. Both I and you learned to be a “man”; so this training is sometimes hard to see through. In my quiet moments I am always a “girl”. I hope you find whom you are.