That must have been horrible, watching your sister get her ears pierced and knowing you couldn't. I got mine pierced the day after I realized I was trans. I was 59.
I think trans women are particularly susceptible to envy, which can have horrible repercussions on our souls. I found something recently that helped me, and may help others. I came across a woman who had many of the qualities I want for myself -- and not just in terms of womanhood. I felt hatred toward her for being who I wanted to be, but can't be. The violence of my feeling frightened me; but then a godsend occurred to me: to forgive her: to forgive her for having the gifts I wanted for myself.
This was the answer to my horrible feelings toward her. It may seem odd, to forgive someone else when they have done me no wrong; but, somehow, it worked. When I shared this with my gender therapist, she was able to come up with an explanation why. I'm sorry I don't remember her explanation; but it isn't necessary.
What worked for me may work for others. Oh, and it's something one may have to do repeatedly.