Do your physio, don't overdo it, knees are complicated.
Just be really careful not to stuff it up, a physiotherapist once said to me "it is like darning in a sock, you try to hard and tear all that darning before it is finished". So don't do more than they say.
I don't believe in taking pain meds unless necessary. Pain tells you when you are doing damage, that's useful.
In september I had an osteotomy, graft and plate of my radius, graft was taken from my pelvis. That was on Thursday. I was commuting to work (cycling to the train station) and working at a desk by monday.
Be cautious, and gentle and it's ok.