I note that your main complaint is low back pain and acidity. As you are working with computers, it is possible that you are sitting on computer for long periods. If that is so, then prolonged working on computers with wrong sitting posture can cause back pain. Sometimes taking painkillers causes gastric acidity. It is unlikely that your acidity is the cause of back pain. On the contrary, patients with back pain often take painkillers, which causes acidity.