I am a scientific type myself having spent almost 40 years now being paid for doing that as a living. I can tell you I basically knew since I was about 4-5 that I was different. Back in the age of dinosaurs being trans* was greatly discouraged. I tried to be "normal" growing up doing normal guy stuff. As I got older the dysphoria got stronger. I tried twice in my twenties experimenting with transition. Twice I stopped in the quest to just try to be "normal"
Fast forward 30 years of "normal". I lost my soul, my life, my joys, my passions. My only function in life was to wakeup, eat, work, repeat. When I lost the only thing that gave me some pleasure, my job as an engineer, I was devestated. The one that followed all I did was be et another paper-pusher in a multi-billion dollar corp, not the hero I always was. The resultant major depression caused me to reflect deeply upon my life and how I got to that place.
The answer, being a trans* was the most obvious root cause. So I sought out support in the backwoods where I was living. I needed to take on the demon once and for all, not dance around it. After a few months I finally found a support group. The first meeting floored me. OK... it may be a lark, try another. THe next was the same result. By the time I was attending my third I knew for sure I needed to be there.
About a year after that, and some time spent with a therapist mainly for other life issues, I was venturing out in the real world as the real me. I once again was feeling alive. Felt joy, happiness. Even some passion as my inner 60's radical was tapped to help with local trans rights issues.
What caused which? I don't know nor care. Western science/medicine tends to insist upon a single causality, I don't. My life till then became what it was for several reasons between early childhood and adult life. Several things I know changed about me to help turn it around.
What does matter is the result. Finally being accept, even embrace, being trans, loosing the shame and much of the guilt, gaining some self esteem, even some self worth were the results of very hard work and gallons of tears.
Also, loosing the Black & White thinking! (still working on that) Again, the result of a single causality thinking and reasoning. "I am depressed because I am trans, therefore I need to transition to be happy" That is B&W thinking. I have not transitioned to full time. Partly from fear, primarily from the percieved realities of that decision. There is a solution in the middle ground that is working for me.
The only way you will know for yourself is to experiment. You don't need a hall pass from a doctor for that. Start be acknowledging that you may be trans, find some local support groups, if possible. (it may take a few before you find one that is right for you) Ask a lot of questions, especially of yourself. Be open and honest to yourself. Be open minded to what you hear from others. Also don't expect one universal response. THere aren't any to these sort of questions. Everyone's experience is different.