The judgement of whether or not someone is trans is if they say they are. I frankly don't understand what I said that makes you think I think it is acceptable for anyone to dictate someone's gender or whether or not they are really trans, but I absolutely don't believe that. I edited my original comment with a clarification.
The story sounds inauthentic to the trans experience and I think they made it up. I don't think the OP isn't trans, I think their made up story doesn't stand up to scrutiny.
The leading theory for what causes people to be trans (or gay for that matter) is hormonal fluctuations at critical points of fetal development. So we are born this way. People can be gender fluid as well, and they may have a different relationship with their gender(s) than I since I am not.
I'm sorry if I misunderstand, are you saying you were forced to present as a woman? If so, I'm sorry that happened to you but it does sound like it worked out for you.
If that wasn't the case, to me it sounds like you were unconsciously aware of your gender but had conscious defense mechanisms that took time to work down.
My experience isn't all that dissimilar, in that I admitted to myself and my therapist that I was "not cisgender", knowing perfectly well that that would definitionally mean I am transgender, but also denied that I was transgender. This was repression, "still cis though" to a higher level. It sounds like your experience was similar.