Bone on bone, get your knees replaced. It will only get worse.
The exercise you are doing will greatly help recovery.
Get the surgery by a specialist and in a hospital that has a dedicated floor for joint replacement.
I had both my knees done at the same time. Best thing I ever did for my knees. I can go up three steps at a time.
(Used to be 4 but that was way long ago)
Bone on bone diagnosis was 14 months ago. My knees still click when I twist them, but there has been zero pain for last 8-9 months. Regular walking (30 minutes 4-5 times a week) is what I am doing. Only medication worth mentioning is baby aspirin (80 mg) on alternate days. But I take it to prevent heart attack, not for knee particularly. There is history of heart attacks on both my parents side. I will
celebrate my 78th birthday this month, never had heart attacks, strokes or arthritis..yet..knock on wood. Totally pain free for several months.
As for knee surgery, if pain comes back and is chronic, only then I will opt for knee replacement. Keeping weight down and exercise is what I prefer.