Hi Hannah, I am going through this right now. Some of it is in mu own profile and posts. My daughter and her wife were easy, as you could imagine. My siblings have been very supportive, although my older sister seems to think I want all kinds of advice from changing my name to getting any surgeries (I just came out to them 5 months ago! LoL).
My wife has been the challenge. We had a lot of problems built up over years. I hid so much of myself from everyone that I never showed or shared all of me with her. Once I did star sharing after 40 years, it was too much. Then I admitted I need to start HRT and it was just too much. She is incredibly supportive and knows I have no choice to have a healthy rest of my life. But she also did not marry a woman (at least she didn’t know she had) and is not attracted to me as a spouse anymore. I get that, but I am not willing to “settle” and have a marriage of convenience.
There are many, many success stories where the couple stays together and thrives, but unfortunately we weren’t one of them. Best of luck with whatever you choose, but it won’t go away or get easier keeping such a momentous secret.