I've been on that Doubt Rollercoaster as well as it's big brother version the WTF are you Doing??? ride for years. Only this past 6 months or so has it calmed down to simply doubts. A fatter way to describe it is Things are sort of working. I am Happy.
My TG support group members have tried to tell me for years not to obsess over the what next? What do I do now? questions. If you are happy and better off than before, then don't feel like you need to do more. Afterall, isn't doing what others expected of you how you got here in the first place?
Also just before any major step, even minor ones, I'd start freaking out. What always calmed me down is thinking again about it and recalling all the reasons why I knew I needed to take that step, for me, for me to feel more genuine, realer.
Apparently, your family already knows about starting HRT, so dealing with that fallout is basically over. Actually taking that step of telling them was scarey. The reality of doing more so. Yet it suspect wanting it was really a need