Yeah -- chair, general ergonomics, excercise, stretching, massage. All good. All mostly missing the real point.
Unless you've suffered a real back injury, your pain is probably at least partly psychosomatic. That doesn't mean "in your head", but "FROM your head" -- there is real physical pain caused by real physiological phenomena, but the major contributing factor is unnecessary muscular tension. BLOW OFF STRESS. Laugh. With friends if possible. Hit things that are designed to be hit and don't mind it at all. Drink in moderation if it's safe for you to do so.
Unless you've suffered a real back injury, your pain is probably at least partly psychosomatic. That doesn't mean "in your head", but "FROM your head" -- there is real physical pain caused by real physiological phenomena, but the major contributing factor is unnecessary muscular tension. BLOW OFF STRESS. Laugh. With friends if possible. Hit things that are designed to be hit and don't mind it at all. Drink in moderation if it's safe for you to do so.