If you've never been fit this would be an opportune time! Bulging disks need muscular support and exercise will do well for your diabetes control! My suggestion would be to find a mat Pilates class. Mat classes are designed to build intrinsic muscle strength. Meaning the small muscles that support vital components of movement. The classes are not a sweat class, in fact often felt to easy by hardier souls. But in my opinion everyone should be doing a basic mat class every once in a while to make sure proper muscles are engaged and remain healthy!
Look around and see if you can sample classes or talk to teachers to strike a cord with them. Usually you need to commit to a 10 week series and that will be a great for you and your back!