Trans and planning to hide it from parents

I love my parents and I don't want to disappoint them or alienate them. I'm also financially dependent on them and am still a student. I'm an adult, but this doesn't change the situation since I'm in school in order to become financially independent. The dysphoria has become overwhelming in the last few years, impairing my ability to function optimally.

Dressing has eased my dysphoria, but not the center of my dysphoria which is my voice.

I want to take testosterone to deepen my voice and then stop. Transitioning fully is not an option.

I have a few questions about voice, if anyone can answer:

For FTMs whose voices have dropped completely to a bio-male range:

Are you still able to access your female range at all?

For anyone formerly on T but now off of it:

Does voice drop occur before masculinization of the face all of the time?
If masculinzation of the face comes before voice drop some times, how reversible is masculinization of the face after going off T?

I figure, everything else can be explained away: hair can be shaved, muscles can be from working out, but a wider jaw would be hard to explain...