Anyone else suffer with back/spinal problems?

Lately the base of my spine (bottom end) and the hip bones are SUPER tender. There is always a pain in the lower end of my spine and its starting to effect my legs. When I walk I get a shooting pain down my leg/s and my knees are always aching. They also give way from time to time while I'm walking. I don't do any strenuous work/exercise and eve at a slow pace my legs and knees hurt. Even just sitting down and laying down Its still sore. I was just wondering if anyone else has had anything like this before or even any ideas what it might be. Last night I was barely able to keep myself standing up. I'm only 28 so its not like have old bones or something.