The problem with lumbar spine surgical intervention is it rarely solves the pain. Sometimes surgery must be done due to something like cauda equina syndrome, other than that surgery should be done only as a very last resort.
Since you had surgery the first thing that comes to mind may be the issue of scar tissue. Anytime you under go surgery the body responds by laying down tissue that is not as pliable as the original tissue. Therefore pain can develop from that. Another issue is the outer layers of the disc do have nerve supply and if the disc has been cut on the research is showing the nerves will migrate deeper into the disc producing a situation of chronic pain.
Losing weight helps many people with chronic low back pain but keep in mind, there are plenty of patients that are thin that have debilitating back pain. Losing 25# is great but if you weighed 350 before and you now weigh 325, that is good but may not be enough.
Long term outlook for taking pain meds is not good either. Life expectancy for chronic pain patient is significantly decreased.
Can Chiropractic help? Maybe IDK it is very hard to examine someone over the net. If you need a referral in Columbus let me know. I would also be happy to check you out an see if I think a chiro can help. Very few people are past the point were I cant make improvements in the quality of life.