Let me tell my story a bit, I too come across this realization suddenly. VERY suddenly! Yes, I had childhood manifestations but was successful in sublimating this like all good little boys of my age. (I am approaching 70. When I was growing up, this was just a fantasy in novels (Edgar Rice Burroughs wrote a book (Martian series) that talks about a male brain transferred to a female body.)
So, when this came up, I was stunned. I have been going to a therapist (I can't emphasize how important this is, putting aside you need a therapist's recommendation to do anything with doctors for HRT, surgeries, anything) and gotten confirmation about my gender dysphoria.
Even said, I went through a period of self-doubt and fear (I have a great family and I greatly fear the effect this will have on them), and nearly talked myself out of this dilemma. Fake it until you die was facing me squarely in the face. And I fell into a depression, gained 30 lbs and began feeling totally hopeless. In a sense, I was moving to a silent spot waiting to die like a wounded animal crawling under a bush. (Spiro didn't help during this time, as I got some negative side affects.)
Not until I decided that faking it wasn't working and embraced my ->-bleeped-<- did I come out of this nose dive. Since then I have lost 17 lbs and am on track to lose a lot more, but more importantly I am happy again. I have purpose and I WANT TO LIVE!
It is normal to have self-doubts and maybe you may decide against transitioning, many others on this site have done so (first thing I learned on this site is that this commitment is yours and whether you continue following the transitioning path or not everyone on this site supports your decision). We will love you whichever way you turn, but above all realize this is part of your expansion of YOUR self-awareness, no one else's.
My surprise at your post is this response from fellow transgenders who feel it is a right of passage (extended period of suffering) that all must go through to be legitimate. Maybe someone could tell me about this... On this website, I have not gotten this strange reverse discrimination, but I got an inkling it existed once, when working with a transgender doctor.
Yours, EvaB