TKR recovery on your own

I'm new to this forum so here's my knee CV:

1. Diagnosed (from X-ray) osteoarthritis in left knee in 1998 after it blew up during a demanding walking holiday in Snowdonia.
2. I don't recall getting much advice from GP at the time. Naively, I didn't realise how important this would be in the future.
By the time I'd had the X-ray and seen the GP the knee had settled down. I cut out the mountains but still walked in the hills.
3. Fast forward to autumn 2011 and following a routine 6 mile walk I had pain in my kneecap which wouldn't go away.
4. The knee had been noisy for many years and I had found standing up for a long time increasingly hard - all insidious signs
of the progress of the OA.
5. I saw a knee specialist privately and he told me TKR in the long term. Severe deterioration (grade 4 bone on bone) in the
patellofemoral joint with some involvement in the tibiofemoral joint including osteophytes (bony outgrowths).
6. I saw the same specialist shortly after (Oct 2011) and asked him more questions about the TKR operation and he surprised me
by offering the TKR operation - I blurted out yes without having really thought that far thinking this was my chance
(I'm only 55 now so I thought I was too young to have it offered to me).
7. A GP came to see me about another matter and off his own bat counselled me against having the op as I was better than most of
his patients. I bailed out of the op which was set for March 2011.
8. I have seen the knee specialist again - he told me that a) He wouldn't have the op if he were in my position
b) I was better than most of his candidates c) The deterioration is slow. d) I have to grin and bear it
9. I have had my other knee and hips X-rayed - all OK.
10. I'm seeing the specialist again on Sept 13 having written to ask him about patello-femoral replacement, which he has never
mentioned - there may be a good reason why it is not a good idea for me.

My current condition:
1. 24/7 nagging toothache like pain on kneecap sometimes with pain at the sides of the knee at the tibio-femoral joint
[I'm taking 2 X 500mg paracetamol 4 times a day and using ibuprofen gel as painkillers]
This pain refers upwards especially at night. If I wake up at night I find it hard to get back to sleep.
2. Virtually full bend and full extension with my left knee for which I am thankful.
3. Walk unaided in my flat but use a walking stick outside - rough ground and even gentle slopes add to the pain.
4. Do 2 X 15 min PT exercises, 10 minutes (in 2/3 instalments) stationary bike and >=20 min walk each day. Knee catches painfully
after about 3/4 minutes on stationary bike.
5. Walks in the countryside much curtailed. Group nature walks out since I can't keep up (and nature walks are naturally
only gentle rambles).

Questions
1. TKR is described as a last resort yet reportedly 90-95% of candidates benefit for as much as 20 years or more. Many become
pain free. I don't understand this apparent contradiction (apart from the hellish recovery process and the risks of blood clots,
infection etc)
2. Does anyone ever "respond" to conservative measures with grade 4 OA?
3. I live on my own and reading the many diaries it is apparent that support from family/friends is needed in the weeks following
the op. I could hire nursing support but I'm not sure what would be needed. Then there is the needed emotional support
that a paid nurse would not provide. Advice please - especially from others who have done this on their own. I'm not convinced that
the NHS and the surgeon take this aspect seriously. For example, I gather you can be sent home with only 70 degrees of bend
and less than zero extension.
4. I suffer from diverticulosis so constipation leads to pain. I have tried opioid painkillers but came off them because of this
and also because of uncontrolled limb movements, hearing voices and vivid nasty dreams - I was becoming someone else. It seems that
to stay ahead of the pain you need to take such painkillers: I don't trust the NHS to ba able to find what will work for me during
the short hospital stay.