I am so glad that things improve for you. I think I always tried to say that to everyone: get voice therapy, ideally from a specialist in gendered voices. It pays off for everyone - people who have no intention for a surgery, those who want to do the surgery and those who had the surgery . Thats because there is so much more to voice than just the pitch.
It is a bit early for me to say, but I feel my voice has softened, changed timbre and sounds more female even at a lower pitch. It is far easier to use a higher pitch now, and I think with therapy it will be not that hard to find a comfortable speaking pitch which does not strain me at all now and which is in a feminine range and which will become normal and natural for me. Before the surgery , I had to struggle to keep that higher pitch and to always "lock up" the lower and relaxed pitches. The lower ones are gone, so I can relax there now and the upper ones are so crazy easy to use. Using voice melody is soo much more easy now, I could not believe it in my first few sentences. I hope the botox is not participating in too much of the changes as it will wear off, but I already know that that point will be a struggle.
My therapist never tried to count the seconds when I do exercises, but in the voice assessment they do count that as well as analyze pitch and range and some other parameters. But the exercises usually focussed on lightness, softness, easyness, breathing, using lots of air flow, relaxing the muscles in the jaw and projecting the voice.