My take, from virtually same position as you (age, ability, newfound desire to improve, coaching).
I have been lucky to have a coach I can go see about every three weeks, and have been doing so for almost a year. He has tamed my gorilla swing to something far more controlled and consistent. It has been hard.
What a great way to learn about muscle memory, the body's desire to repeat actions in spite of your brain's desire to do something different. I needed to learn how to roll my wrists, swing inside out, drop my hands, on and on. Gaining consistency across all these changes has been a long, long road. Coach does this without tech, but I try and add that other places (real feedback away from his expertise).
All this to say, what I started out as thinking was a few lessons has lasted a long time. My focus now is on the process and not all on the outcome. This is hard stuff. I'll know when I have reached my goal.