Hardly any proverb has so much truth. "As you make your bed, so you sleep".
Now let's be honest. What does your mattress look like? A friend of mine recently complained about back pain and I asked him about his mattress. Well, and that was still from his childhood days! 12 years old, completely worn out, just old.
Then we went spontaneously and bought a new one. There are offers in all price ranges, all qualities. Find a good shop and get advice. Doesn't have to be the most expensive, but new is always better than a completely worn out sleeping pad. Well, and a few days later I asked my friend on the phone how's it going with the back?
Wonderful, he said, it was a good investment. Good night!