First off, is this a guess on his/her part or did you have an MRI to determine that you have a bulging disc?
The exercise you speak of is the McKensie exercise that takes pressure off lumbar disk, sort of decompressing them naturally, helping to realign things. If it works for you great!!! Keep it up. There are books on this technique out there. I have them myself. They did not help me at all, as my issues were more pronounced.
If you come off the medrol pack and things get swollen again, you need to be referred to an orthopaedic surgeon to figure out what is going on in there. This does not mean you need surgery or that seeing a surgeon means he/she will want to encourage you to have surgery. Doctors today try and do everything they can to keep patients out of the surgery room and exhaust non-surgical treatments prior to discussing surgery options, unless issues are very severe.
Also, a physical therapist can greatly help you learn proper exercise techniques that will help you.
Welcome to the boards.. and please come back again and let us know how you are doing. Take care. Tammy