I agree, there is much more involved than just the knee/leg. I still have occasional mini melt downs of frustration, though nowhere as intense as earlier on, as this is not how it was supposed to go.
I’ve had a weight gain also, and for the first time, diet alone is not reducing my weight as it used to. I think I have much fewer ADLs than I used to, but it’s hard with a limited knee, and now I have a painful heel making walking difficult.
I hope you at least feel that your leg is straight now.