I too find aches and pains, stiffness etc. part of growing older. I am 73 now. However, I have found a easy and cheap remedy for some of the stiffness in the morning. Drinking more water!
Two or three large glasses of cold water, by large I mean I use a glass with a capacity of just under 5dl in addition to the other fluids I drink in the course of the day, makes a very great difference and may actually also improve short-term memory!
I find it most convenient to drink the extra water fairly early in the day, unless I intend to go shopping or out anywhere else in the forenoon, On the days, I do go out to places were I know it will be difficult to find a toilet, or one that is clean enough for me to want to use it, I take my glasses of water in the early afternoon.
Don't postpone them until late evening! You will be trotting all night if you do, unless an even more unfortunate result occurs!
As you can still sit on the floor, as can I, may I suggest a little PT? Nothing too strenuous, but stretching and flexing exercises do help too.