I still have a little stiffness today. Annoying. I am sure tomorrow I will be better. it's not terrible anymore, just a bit of lingering stiffness. I actually have a really firm mattress. It was cheap and it's foam. One of the newer types they sell on amazon. It's not very good, so i think a replacement is a good idea. Keith is right, it's your back & your body, sleep is so important to your overall health, and you do use it a lot. I should invest in something decent.
The pillow situation is another one entirely. I had a lot of different ones. Even ones specifically for cervical neck pain. I've had foam, a variety of them too. I recently got a smushy one and I prefer it. I sleep on my sides mostly. I don't know what I will do, but I wouldn't be surprised if a mattress is a worthwhile option to try. I've actually had these stiff necks with every mattress i've had though, over years and years. They just pop up one morning and you can't turn one direction without a lot of pain.