Lower Back Pain. Of it in coming future.

I'm suffering from back pain in lower side of my spine and its one sided only. The pain travels to the left leg also. Pain severity is MODERATE+. When i do exercise for back pain, it goes away but it comes back when i leave the exercise. This is happening to me for last 3-4 years. I took medicine for it and it gave me relief but soon after the completion of the 3 month dosage, the pain comes back. It all started when i started sitting in Namaaz's JALSA (in Sujood) posture, the left leg has to be bent and the vein of the left leg too all the pressure of the body. This starts tinkling in my left leg and soon developed into this back pain. But then i left that posture and start taking medicine as per doctors but it comes and goes in a while. Please recommend me a permanent solution as I'm afraid of it in coming future. Thanks.