Listen to Josephine my dear. You most certainly need your pain meds, and are not a whimp!! As far as PT is concerned, you don't need a CPM machine at all to get great results. And PT should be easy and gentle and not done for hours at a time!!
I was extremely lucky. With the push for aggressive PT here in the US ( which I just do not understand ) I got a PT who recited the BoneSmart mantra to ME. And this was before I was a member here!!!
All he did when he came to my home was give me a fabulous message of my leg with a rolled up towel under my knee for a good 10 minutes, then ask me to gently bend it back myself until it was uncomfortable but never painful. Then he would measure my ROM.
He even scolded me when I did too much!! He told me just what everyone here has been told. A swollen knee will not bend, and trying to force a swollen knee to bend just causes more swelling. That all that swelling from overwork can cause problems.
I never had a CPM machine either. Not in hospital, or at home. I was blessed to have a surgeon and PT who knew how to rehab a TKR.
After reading all the posts and seeing all the PT that others were doing, I felt like a slacker in comparison!! But I soon realized they were spot on right!! I had a good recovery, and one that didn't involve pain and frustration because from the start, I was following the BoneSmart mantra even though I didn't know it yet!!
My flexation and extension came quickly because I was not being forced by PT to overwork my knee. I elevated, iced, and took it gently, and just let it come. And I was never made to feel I wasn't doing enough 'hard work'. I hate it when surgeons and PT makes patients feel guilty if they aren't forcing their knees to bend, bend, bend!!!! It's NOT the way to go, and it's terrible.
Let that knee heal. And let YOURSELF heal!! This is a major surgery that takes a huge toll on not just the knee, but our whole body and mind.
And never obsess about the numbers. Slow, gently, and easy win this marathon. Enjoy the downtime and don't try to force your body to do what it doesn't want to. Sleep when you feel the urge!! Don't get up if you don't feel like it. Heck, don't do anything exept stretch your knee gently and bend a bit gently every so often. For the first month this is all your body is going to feel like doing anyway.
Go with your body, and good things will come.