@tracy70 - I'm wondering if there is a reason that you are only starting PT more than 3 weeks after surgery? Was this your doctor's recommendation?
From my experience with my two TKR's, my first PT appointments were within three or four days after surgery, 3 times a week for a month. There was a PT evaluation the day of surgery, a few hours after the procedure where they tested my knee movement and gave me some sheets of exercises to do at home, some of which were similar to what the PT therapist had me eventually do. But I think I gained more from having my therapist's initial and constant guidance in pushing past what I might have thought were my limits. Especially with the first knee, I would not have known what to expect or how hard I should be working it. He also kept stressing the icing and elevation for the first month and even later. My PT home exercises took about 45 minutes and I was supposed to do them twice a day. At first it seems like you are not making much progress, so it's nice to have a cheerleader/trainer giving you motivation, and so gratifying when you find you can actually do an inch or two more of a movement. I think most of my recovery occurred in the first three weeks, and the rest was improving and fine tuning the leg strength and knee range of motion. I did keep going two extra weeks, for a total of six weeks of PT, but the last weeks I only went twice a week.

I sympathize with the lack of sleep, so hard when you can't get comfortable. Often I slept with the ice bag over my knee. That helped a lot the first couple of weeks. Eventually I used a pillow between my legs, maybe the wedge is too hard? It sounds though, that your surgery was more painful than mine. All I even felt was a big dull ache, no sharp shooting pains.

I hope you heal and recover your knee strength. I am glad I had both of my knees done, one year apart. We have a lot of stairs in our house, and the knee pain and grinding when coming down was awful. Going up and down stairs on my new knees as they healed was good therapy in itself, once I could manage the angle.