Well, all I can say is I was born at the ripe old age of 54. That was when I gave myself permission to transition. If being trans shortened my life it's because I let outside influences prevent me from being who I really am. Stress kills and I was almost dead a couple of years ago because of it. Once I stopped listening to everyone else and listened to the real me inside I dropped a ton of baggage, which was filled with anxiety, resentment, denial, hatred and misery (to name a few).
I don't know how I'll fare on longevity but I can say with confidence that my life was extended the day I chose to be me forever.
Life shouldn't be measured in quantity of years, it should be measured in quality of life.
Julie