Lay off the caffeine, the last thing you need is something that is going to wake up those nerves.
If you take pain killers of any kind, go to bed and stay there. If you move around while you are on pain killers you will only make matters worse 'cos you wont be able to feel that you are straining things more.
Don't keep your wallet in your back pants pocket 'cos that will skew your spine (actually a chiropractor did tell me that one).
Find a small pillow or cushion to put in the small of your back when you are sitting. Especially in the car.
WHen you are picking something up, bend your knees, don't bend at the waist. This takes practice but it is worth it.