When sitting I favor leaning to my left side, same when working from desk. Now after 5 or so years, it's creating lower back discomfort. X-ray clear. I work on couch using laptop, and my way of sitting is left foot on my right new while I am leaning towar

Common problem. You have poor body mechanics and your musculature need retraining. I imagine you have abused your back. Check with your family physician and get a referral to a physiotherapist. You will be amazed at the positive change.