thank you for sharing your complain, dear friend your back pain is muscular pain. you should start heavy gym exercise which hurts your spine. when you lift heavy weight, all weight of your body will be balanced by spine and if muscles of your spine are weak then spine will feel much load and will cause pain. so first you should do such exercise which will make strong the muscle of spine,rather than heavy weight lifting exercise. hope this answer will be helpful to you. for more queries plz don t hassitate to ask. get well soon.