Well that sounds like no life at all. You're right to come on here for help. Things are not right, and it doesn't sound as if your surgeon is helping.
I'm tired of people asking or telling me that they know so and so who had both knees done and they're doing great.
Oh I know this territory all too well. It's bad enough that we feel disappointed in our lack of progress, and people's well-meaning comments just make it worse. Find a phrase that will cut them short and save yourself at least that little item of misery.
A small percentage of us have knees that don't bend well. There are three main reasons why this can happen. One is the surgeon didn't get the knee in right. Second is there are adhesions or scar tissue. Third is there's an infection or other disease process affecting the area.
Assuming the best, that you had scar tissue and thus the MUA, be assured that your ROM is fine and will get better on its own without any effort. So if you're 115 on your bend, what are you on extension? Are you able to fully straighten?
You mentioned that you worked hard for your ROM. There's a Catch 22 in this business of reluctant ROM. When PT accelerates to get the knee bending, it actually has the opposite effect. I'm guessing that early on your knee was "behind" the norm for ROM and it was then that the aggressive PT began. That level of PT does not help because it's hurting a knee already injured during surgery. Thus there is a backlash of inflammation, swelling and pain, which interferes with ROM, which the PT approaches this aggressively, and thus a vicious cycle has set in. Then they do a manipulation and continue this unhelpful approach so you can "keep" ROM gained in MUA.
I found that the efforts of pushing my knee resulted in a lot of pain. At five months I was just past 90 degrees ROM and taking 1/2 percocet every 4-6 hours. When I took a vacation from PT at six months, my pain went away. I never did formal PT again. It was not needed (except some efforts since then to get the quad firing better).
Now your case sounds a bit extreme, so before I continue to guess what's happened, please fill us in by describing your ROM at various points of your recovery, your sessions with physiotherapy (frequency, length, and what was done), PT at home, and how much/how often/what drug you're taking now. It would also be informative to know where you had your knee done/what state/hospital.
Some parting advice -- trouble with TKRs are almost always soft tissue. The bone/joint part got fixed, but they injured the soft tissues in the process. It's the soft tissues that TKR recovery is all about. So as we help you sort this out, go back to as much icing and elevation that you can do, rest, massage, margaritas, watching your favorite movies, etc. Your knee needs a knee-cation!!
And we will help you out of this awful fix. Thank goodness schools ends soon!