We recently added a 3" memory foam mattress topper to our bed. At first it was a bit strange feeling, but it’s been incredible. I bought it on e-bay for 90 pounds plus 20 pounds s&h. (my pound symbol doesn’t display here)
It’s been one of the best things we ever bought. The other best thing are the latex pillows I bought about two years ago. I got whiplash in a car wreck many years ago.
I’ve experimented with orthopedic pillows for over 20 years, and these latex pillows win hands down. Not only (like memory foam) do they react to body heat and mold to the contours of the body/neck, but they’re shaped like normal pillows, although they’re fairly heavy for pillows.
I’ve read that these sort of pillows don’t harbor dust mites either. They were expensive. I got them on sale for 35 pounds each. They haven’t lost a bit of their shape.
Between the memory foam and the latex pillows, we’re getting the best night sleep ever!
I don’t suppose I’d add a topper to a mattress that sounds like it’s on it’s last leg as you described yours is, but anyone else who has a firm mattress, but finds themselves tossing and turning due to joint or back pain, this is a great solution. I splurged for the 3" topper, and the fitted sheet has to really stretch to get over it, but next solution will be purchasing some of those deeper fitted sheets to accommodate the extra height.