Disc
dehydration is common with normal aging, and is likely not to be causing your symptoms
I cannot give you accurate information on your scan without seeing it, but if the report is correct, the disc bulge does not seem to be compressing the spinal cord or roots (lumbar stenosis). Certain positions, like extending the spine can reduce the disc space and cause the space to become tighter, this can cause some positional symptoms. In this case sitting forward/riding a bicycle position can increase disc space and relieve symptoms. If significant lumbar stenosis is confirmed by MRI or myelogram then surgery may be beneficial.
Alternatively, other structures ie soft tissue/ligaments can be responsibel to chronic back pain too - not just the nerves/spinal cord. Unfortunately it is hard to differentiate (although less likely to be neurological) sometimes especially if there is no evidence of spinal cord/root involvement by MRI or EMG.
Other procedures for chronic 'discogenic' back pain are available like IDET or prolotherapy (see question answer from last week re IDET) but the scientific effectiveness of these procedures is not confirmed.
Physical therapy and weight loss (if overweight), posture training etc is very important. Surgery is not a cure all and can result in a worse situation than before.
Good luck
I'll review the posts you've mentioned.
Thank you for your time
Hawg