Good Luck Parky, I'm the same age as you, (but I'm not so slim or fit..!!). I'm sure that your general good health will help in your recovery.
I had (both knees)TKR 10 & 12 years ago. I persevered with the physio & think that helped. I, still, have very little pain, much less than before ops., I am mobile & am fine walking, I find my knees don't like standing still for long periods!
I was loaned crutches after each op.,for a few weeks, but didn't have any other "aids".
Let us know how you get on, pm me if you need to.
Best Wishes