I really should get a new mattress. But as a temporary (?) fix, I have got myself a mattress topper. And not a cheap one - but that's OK, because I think I can claim it as a wellness expense at work. And so far so good. I haven't been waking up with back or shoulder pain, something I had been suffering from prior to having the topper. The one drawback, the memory foam mattress topper I got must have a depth of about 3 inches. So that on top of my mattress makes my bed look weirdly tall, and it also means that my fitted sheets don't really fit properly. But that is a compromise I can live with if it means a better night's sleep.