You may also consider seeing a good physical therapist, I would think they could set you up with a good exercise program.
You should see a physician along with a mri it could give you lots of information about what is wrong with you back. I have a bulging disk in lower cervival vertebra which was herniated at some point, the X-ray were okish and did not helped find what was wrong. Both my posture and gait were really bad, my feet needed some care and I've a bad knee that never completely recovered; no matter a surgery. Andd while sitting... terrible habits... Swimming improved the matter for me it as it promotes symmetry and self-aware though decades old habits are not changed easily, it might as complicated to change habits and brains bias toward an improper posture (which it considers normal) than for the body to adapt (muscles, ligaments, bones structures), etc. I'm 41 now and I decide to take the matter at hand (taking care of feet and posture and back) BUT whereas there is some self medication going on (through product avvailable without a prescription) I got some professional assement of issues. For the herniated disks, I needed some anti-inflammatory drugs for a short perod of time (a neck brace for sleep ure woud have helped). Once the crisis is over the disk is still bulging which means the effects (bad postures, improper exercizing, etc.) will trigger the same consequences. I would not advice you to see a chiropractor or ostheopathic, etc, back manipulation require special care if there is an issue with you spine, disks, etc.
