It's cold to sleep under a tent. I have a damp pad, a shop and a sleeping bag, but I still feel cold and backache. Please ask the great god to answer.

I want to say, if your waist already hurts, it's no use adding any blankets and quilts. Cold and dampness invaded your waist. I suggest you see a doctor as soon as possible. If it is inconvenient, you can find someone else to rub your waist 10-20 minutes, and it will burn. But this is a temporary solution, not a permanent cure.