> It hurts my back. I've actually gotten up in the middle of the night to sleep on the floor before when the bed's been too soft.

I have an old memory foam mattress that is getting less and less firm. After waking up with a sore back at 3am 2 nights in a row I flipped it over and slept on the bottom, much firmer side. Has been working perfectly for the past week while I wait for my new mattress.