Hi and Welcome!
The thing about this recovery is, for many of us, the more we push early on, the more it sets us back. You cannot bend a swollen, painful knee, and overworking it to improve ROM, just causes more pain and swelling.
Since all your efforts thus far have not worked, consider trying a different tactic. Stop all the exercises, and just very gently bend your knee, no discomfort at all, just give it movement. Go about your daily activities and let those movements be your exercises, and forget about your ROM. Sounds crazy, right? But, for some of us it works just fine. Here’s an example:
This is what one of our members, TortiTabby, experienced:
(Just so you know, ADL means Activities of Daily Living.)
“At my six week appointment this is what my OS wrote in my visit summary: "
She reads an online website called Bone Smart which states to not push through pain following knee replacement. If she were to follow this direction, she will have to learn to live with a knee that only reaches to 85 degrees of flexion. I believe this website is very misleading."
It has now been 20 weeks
and all I do is ADL and this is what my ROM has done:
3.5 wks: 75
6 wks: 85
7 wks: 90
10.5 wks: 95
14 wks: 100
17 wks: 105
20 weeks (where I am today): 110
I am so thrilled it keeps improving and improving and I know now that I will get to my goal of 120 (or even better, dare I say!)

So, if a OS or PT bullies you into thinking your ROM will not improve over time they are wrong. By the way, I haven't been back to see the OS since that horrible appointment at 6 weeks, but I sure am going back when I reach 120 just to say, "Ha! You were wrong, BoneSmart was right!"

“
And,
“Just an update for those who are apprehensive about gaining ROM:
It has now been 26 weeks
and all I do is ADL and this is what my ROM has done:
3.5 wks: 75
6 wks: 85
7 wks: 90
10.5 wks: 95
14 wks: 100
17 wks: 105
20 weeks: 110
26 weeks (where I am today): 120!!!
I did it! My goal of 120! No "pushing through pain", no PT after the first 3 visits, and most importantly to me: No MUA! My surgeon who said I would never get beyond 85 ROM without pushing through pain was wrong, wrong, wrong. I'm excited to see if it gets even better.

“
Regaining our ROM is more about Time than repetitions of a list of exercises.
Time to recover.
Time for pain and swelling to settle.
Time to heal.
Our range of motion is right there all
along just waiting for that to happen so it can show itself.
In the general run of things, it doesn't need to be fought for, worked hard for or worried about. It will happen.
Normal activity is the key to success.