With all that heavy lifting, you've compressed your spinal discs. Physical therapy will probably help. Moist heat packs applied to your back will loosen muscles. I'm sure they're very tense. Stretching excercises will help. One important thing for your would be to get another line of work. A doctor's recommendation for this will get the state to pay for months of retraining. MJ is a different issue. I'd go for physical therapy and a different line of work if I were you. If you keep up the heavy lifting, you're going to end up requiring surgery. Trust me, I've been there. I changed jobs to save my spine.