Hi,
I'm sorry you are still having a hard time.
Your pain relief medicine is still inadequate and you need to push for more effective treatment. No, it isn't just you. This is a big operation and it needs proper pain control.
Please don't worry so much about your ROM. It doesn't need to be measured every time. It's just a number and it really cannot improve until you get rid of the swelling. Some physical therapists get hung up about ROM - that's their problem, not yours. Sometimes I think it is just so they can justify their existence - they need to show progress on a piece of paper.
Also, there is no such thing as a magic "window of opportunity", within which you have to get a good ROM, or all is lost. Many of us can tell you that ROM continues to improve for at least a year.
Try to think of your knee as being like a hosepipe that is filled with water - it really can't bend well until the water has gone. The water keeps it stiff, just as swelling keeps your knee stiff. Keeping on working hard at trying to bend that knee can't help and it may even slow your progress - the more you work at it, the more the tissues get irritated and then they swell more.
For what it's worth, I think you should stop all your physical therapy for a while and just concentrate on reducing that swelling. Just do gentle bending and straightening at home, combined with ankle pumps. People in the UK recover from a TKR by dong just that. They have very little formal physiotherapy and their end results are just as good.
Resume the PT once the swelling is down - and make sure that your therapist never pushes you until it hurts, or to the point where you get swelling after PT.
Best wishes, my dear. You are over the worst. Be kind to yourself, and insist that others are kind to you.
Caryl