@sr108 - Well, I think this line answered your own question, "Hoping someone else has had this experience or maybe there are good days and not so good days? "
Yes, when I rehab (10 0r more ortho surgeries) I refer to the beginning of intense PT as "Two steps forward and one step back."
Remember, joint replacement is a major assault on your body - bones, muscles, ligaments, tendons and nerves, as well as anesthesia & blood loss. Then, you stay still, using ice and elevation for 3 weeks, so muscles atrophy and the body tightens up. And suddenly - it's time to get serious about upping the PT - and it hurts, a lot!

Here is what has worked for me:
ICE, up to 12 hours a day at this stage. It keeps swelling down and numbs the angry nerve endings.
Elevate, whenever you are not on your feet & moving, the knee should be up - at least above your hip or else above your heart. My doc told me at least for 6 weeks, longer if it continues swelling.
Control pain. By this point you are probably alternating Tylenol & Ibuprofen. Keep on doing it, especially before and after therapy sessions. I did it for over 3 months after my last hand surgery, 24/7.
Do your at-home therapy 2 or 3 times a day, no matter how bad it feels. Once a day is not enough to make progress.
Walk - at least as far as recommended every day. Challenge yourself to increase a little each day.
Rest - Your body is still healing. Once or twice a day, nap for 30-60 minutes. Phone, devices & TV off, in recliner or bed. Sleep is restorative & short naps will not interfere with night-time sleep.
Distract - Find something you can do while seated & elevated to keep you distracted so you don't dwell on your pain. (Not recommended - endless screen time or news-binging. Reading endless posts about pain and suffering. Recommended - read, engage in a hobby, learn a new (sedentary) hobby, chat with friends on the phone.)

Hang in there - breaking up newly forming scars HURTS, but you will be happy later to be able to move more freely. Forcing the new joint to move farther each day HURTS. Healing muscles can hurt or ache. Expect there to be some tingling, numbness or pain while the nerves heal. This is normal and varies from hour to hour and day to day.
You will gradually feel better until one day, you look up and say "Wow, I haven't thought about my knee for a whole hour."
Are you having a better day today?
Sue