Yes you are in a very tough place, most of us have been there, our best wishes are with you. I had a similar story to Devlyn's and chose not to tell my mother. In her last days her dementia was bad enough that I was able to sit with her and she was unaware of who I was. But that is another story.
What you choose and the nature of your transition is all about where and how you balance your priorities. There are folks here that needed to go all the way with hormones and surgery and totally out in their lives and there are those that know inside who and what they are and live presenting in their birth gender for the sake of family. Each of their choices has costs that we must balance and pay. As you wrestle with your journey, you can find folks here on Susan's that will share their stories to help you understand your options, please reach out to us.
May you find blessings in your choice,
Tia Anne