I split your reply from a thread in the Hormone Jungle and moved it here to the Hormone and Menopause Central message board. I think you'll get the best support in this forum while you're still recovering from surgery and adjusting to hormone therapy.
There are definitely doctors who believe once the uterus is removed progesterone isn't needed. I think that's because progesterone is
necessary for anyone who has a uterus and is using estrogen. Using estrogen unopposed can increase the risk of uterine cancer. Without the uterus progesterone doesn't have
to be used but many of us find we feel better with it than without--regardless of what the doctors say.
We're not all the same when it comes to hormone therapy needs. Some women do very well on estrogen alone. Some need estrogen along with progesterone and/or testosterone. Usually we start out on estrogen only and work to get as balanced as possible on it before adding in additional hormones. It's easier to work with just one hormone at a time because symptoms of too little or too much can overlap, making it hard to figure out which hormone needs to be adjusted. It helps to keep a journal during this process so you can see how you're doing over a period of time. That beats trying to remember how you felt on any given day.
This link is good to refer to: Too Much/Too Little
There are some good articles about progesterone, as well as other hormone topics, in this link: Hormone Jungle
I hope this helps!