Judithh580, This is so familiar. I had surgery back in 2016. It was a 2 1/2 hour procedure (Not knee replacement) and I couldn't turn my brain off for quite a while. I think it was the anesthesia and pain meds. I sweated terribly for a few weeks and had crazy dreams after the surgery. My thinking is that it takes your body a while to "expel" the anesthesia & pain meds. I was exhausted & restless. It took a while. I had to rest during the day to recover. Sleep finally went back to normal after a few weeks. I feel like it will for you too. Your body has gone through a lot and rest is healing after surgery. I'm so sorry you are battling this. Praying for you....