I'm not a medical professional so I can't confirm or deny your hopes in any way. But when I got my preliminary blood work done it turned out I had low testosterone even for a female-bodied person. Yet, I was pretty hairy and didn't have a particularly feminine voice; I also had a few sparse hairs on my upper lip. If anything, I was expecting to have high natural T levels. Now that I'm on T I'm getting hair everywhere, even on the back of my hands. In fact, body/facial hair was one of the very first changes I noticed. So, basing it off my experience, I'd say you probably have a good chance of getting quick changes too, especially since your levels are already high. That's pretty cool.
I know what you mean when you wanted to take back what you told your mom. I felt the same way. I think it will always feel kind of weird with family, or at least with our parents. But it sounds like she's quite accepting. It sounds like you've got a lot to look forward to, and be happy about. So keep your head up man. It's not going to be an easy road, but it helps to have people supporting you. These things take time.