Have you looked at the hip replacement thread on here which is on its second one as the first one filled up !
Although it says hips there are knees on there too so certainly worth a look.
Also you will hopefully get some response on here.
I only have experience of hips but I think it’s accepted that the recovery time for knee replacement is longer as they are more complex joints.
Having said that, even after my hip operation, at the one week stage which you are at, I was still saying “what the hell have I done?” as I was still in quite a bit of pain.
Honestly though it does get better, it really does.
They are fantastically successful operations for the vast majority of people, transforming lives almost beyond belief.
I was lucky in that, although my hip had deteriorated to a point where it definitely needed to be replaced,I only had a five month wait from when I saw the surgeon to the operation. In fact I was still doing the supermarket shop a week before the operation, before I had to stay in away from people.
This was just before Christmas when covid cases were quite high, and a couple of negative tests were required just before I went in.
I am sure you will gradually feel better and I hope you find the threads useful.