As others have said a lot of it sounds like the fibro.
I've found osteopaths great in the past so definitely worth a try. They can tell all sorts of things and, like physio, the asking and looking is important. They need to get an idea of what the problem is before they start to try to treat it. Just little things like your general posture, the way you stand, walk and respond to simple things can tell a lot.
There may be other options they may think could be suitable like acupuncture.
They can also help with aides, including occupational health referrals, and could look at things like aides to help you get footwear on, grabbers etc...
Physio could also help with aides for getting about like a walking stick.
It can take time and effort though. I found out from physio lately that my pelvis is tilted and I have lumbar lordosis, as well as the knee issues they are helping me with, and have given me exercises for it to try and counter the tilt and work and strengthen the muscles round my knees to try to help it and associated pain. Don't underestimate the impact that parts of your body being out of whack can have on you generally.
Has anyone suggested any longer term pain relievers such as amitriptyline or even gabapentin or pregabalin? A pain clinic may be a good idea.
If you are getting swelling, has any inflammation been picked up in any blood tests?