you might be having any of the back related problem and the description that you have given is insufficient. do specify if the pain is radiating to your legs or not. have you had any type of accident , fall etc. that caused the onset of pain 7 years before. you should see a doctor and get treatment. you are 33 yrs now imagine what will happen if degeneration kicks in. so do not fool around. get professional help. mean while use any natural oil for light massage
for 5 mins after that apply heat to the area. this may give you a bit of relief.
hope i was helpful