Suggest Treatment For Lower Back Pain

hi im 17 i have lower back ache had it for over a month now. the pain comes and goes as it likes it gets worst as i move about and stand or sit for long periods of time. also right at the bottom of the back if it is touched it feels like the bones bruised. i have been the doctors many times about this, they only seemed to be concerned if i get any pain in the legs or bum with the ache. i have also been on different types of tablets like napoxen and difflofenac co-codamol, paracetamol etc no differnce when i use them they seem not to work. i am awaiting physio at the moment as i have had the pain for too long. what could this pain be?