I'm so sorry for your painful days and nights right now. I also hope you were not under the impression from my comments that I had an easy go of MUA after-effects. Pain is relative, and I was relieved that the MUA results didn't hurt any more than the original surgery did. However, I dealt with increased swelling and pain for several weeks after the MUA, particularly since my doctor also prescribed "Aggressive PT." That's what made me join BS! I was doing lots of exercising at home and aggressive PT daily per doc's instructions, and I was at the end of my rope.
I noticed that you have been trying to get your pain under control with medications. At the time of my MUA, I was still using opioids plus Tylenol on a regular schedule. To manage the pain, you may need to temporarily think of this period of your recovery as "going back to early days." Keep the medication constant and don't let it lapse. "Early days" means lots of rest, ice, and elevation, and not doing a whole lot until the swelling decreases. That was my downfall before finding this site. I was battling with too much activity and exercise and increasing the swelling while not improving my ROM much. Once I seriously decreased activity at home and increased icing and elevation, I started to see better results and my comfort level also increased. (I kept doing the PT.)
I know it's hard to think of yourself as going backward, and I fought that image on this site whenever someone suggested it. Truly, though, your MUA has sent you back several squares on this game board of TKR. I believe that you will eventually reap the benefits of your MUA, but for right now, treat yourself gently, rest a lot, and don't compare your progress to others who had their initial surgery around the time of yours. We understand that those who experience a DVT or other complication will need to do this babying, but we don't apply it to ourselves very well.
It's scary to come out of the MUA hearing that the doctor got a good "bend," and by the time you get home, your knee has stiffened up. What you are describing happened to me, too. For quite some time, while the swelling from the procedure was still present, I couldn't bend very well, was very stiff and dealing with pain, and very depressed that it hadn't seemed to work. I hate to admit this; it seems silly now, but I truly thought that I would walk out of the hospital after the procedure and my ROM would be great! In fact, I thought that maybe the 2-hour car ride and not getting right into PT the first day (as my doctor had wanted) might have caused me to undo the results the doctor got in the operating room! (I'm good at blaming myself.) It took me quite a while to gain acceptance and peace with the fact that the procedure caused swelling and set me back a bit, and that I wouldn't see good results until I got that swelling down.
Give yourself the gift of time; manage your pain; try to relax. The rest will come; I'm sure of it.