I am 9 months post op and still take some opioid at night to get my leg to ease up to sleep. I work 9 to 12 hours a day, by the time I get home and cook dinner, my knee is swollen and hurts.
I am glad I don't have to have my other knee replaced. My left knee was a partial, I breezed through that recovery. I would not go through this again.

TKR is overwhelming, isn't it? I have been where you are, as have many others. Do beware of what "they say"! That phrase usually is what I think of as a placebo reassurance. It doesn't mean anything other than that They don't know. Based only on my own experience, I am sorry to have done the TKR and won't do joint surgery again. The surgeons are not forthcoming about the reality ahead of time. Not all surgeons bother to provide presurgical education, and it is really needed. Surgeons are only useful in the OR, and afterwards you are mostly reliant on the therapist and a family doctor. Pain control is a big issue. I had bad reactions to the opioid and when I called desperate for help was told to come in for my regular appointment in a couple of months! There are pitfalls all along the way through recovery. All those muscles, tendons, ligaments and nerves can get injured or temporarily inflamed. They all have to adjust to moving in different positions because the surgery changes the length and alignment of everything in your leg. Also, as you start to walk more you can get back pain. It's mostly all temporary, but the timeline can be really slow for a lot of people. It's not unusual to get frightened and depressed. All you can do is be kind to yourself and make some appointments with other doctors than just the surgeon. There are several medical specialties that deal with legs and injury to soft tissues. Get some different perspectives. If pain is a continuing issue get to your family doctor for quick help. There are also pain specialists in medicine if you're really concerned. And don't overlook changing physical therapists if you are hurting and not making any progress with the exercises they have given you. There are different approaches to healing a knee after TKR. It makes good sense to look for a therapist with more experience or a higher level of certification, like board certified or a Ph D. Small things can help...having a supportive friend, doing deep breathing exercises to calm the injured nerves and oxygenate the tissues, being sure to rest frequently and eat right. Sleep is always a problem after TKR so take a nap and impress on your family to be quiet then. All the icing and elevating really does help. Don't overdo it with pushing through pain and trying activities you aren't ready for. Everyone heals at their own speed. Listen to your body. Move it often, but gently. If Tens isn't working now, it might work in another month. Maybe shockwave would work. It does speed up healing. Ask if you can use a topical cream for pain, like Voltaren, or try lidocaine patches (I loved those--12 hours of relief!).
Despite the perfectly reasonable anger you feel, there is nothing to do but go forward. I wish you all the best. I felt just like you. I wanted the **** leg amputated too, except then I wouldn't be able to play my Steinway. I found out late that the therapy I was given was injuring my leg over and over. I have moved on to a different program and am finding slow but steady healing. I still have some flare-ups, but other patients report that too. There is an army of people out there struggling forward like you. And no, the doctors know only half of what you need them to know, but that never stops them from going right ahead with major, risky procedures on other people (not themselves). So keep doing anything you find that makes you feel better. Expect the healing roller coaster to go on for months. Expect more surprises. Build out a support group if you can. I got lucky and found my nephew, whose patience, generosity and kindness kept me alive. Lastly, anger can be fuel to keep fighting and to keep researching for more help. I couldn't walk for a while, but I could read, and in the end that got me where I needed to be to start over. There isn't a time limit on getting better, even if it's in small steps. Just keep going forward. Best wishes.

Be glad the drugs work for you to get some sleep. After 3 days post op was vomiting all night, tried to see if it was oxy or tamerol...was both. So had to revert to tylenol as the pain reliever. So probably did not firce my knee to bend as far as it should. Am at 110°, not considered a candidate for MUA. So now 1 year post op, I can play golf, tennis, pickleball. Biking I am up to 25+miles but feel every rotation on the surgical knee. I think hiking is out now for me. And depends on the day/time whether I can walk down the steps like a normal person, and I live in a three level home. Is great just after a long shower, but that is short-lived. After surgery I thought my recovery was great, was walking from day one, up to two miles a day, just brought a cane along to be safer at the street corners. Of course that probably resulted in more swelling and thus less bendability for my exercises. Good luck with your recovery.

I had mine done in March of this year at first I regretted having it done. My lower leg had bone pain I still get it but it isn't as bad now. I stopped physical therapy after 5 weeks because she would lay me on the table and would push down on my knee it was excruciating I quit therapy. I have been riding my stationary bike and doing stretching . I am doing good still have issues with stairs. Hang in there it does get better.