My heart goes out to you, as I have only been diagnosed with 2 of the conditions you (DDD or dengerative disc disorder aka sliped discs, and Spine Arthetis - which the latter is theorized to be Ankylosing Spondylitis but further testing would need to confirm this).
Finding what works can be one of the most frusterating things, and then FINALLY you find that one medication that actually works (for me it took years but part of this was due to my stuborn refusal to be treated for some time). I think the big fear then is that we will be removed from it.
I think the most important thing to avoid this is a common sense thing, but we seem to become like a stone when we talk to ouir doctors sometimes and the needed information doesn't get out. He or she needs to know that this medication really works! Keep a pain journal and show the results to him or her. Things like explaining that the medication has tolerable side effects, show physically any medication left over, and keeping a written pain journal are key here. I know a lot of people are affraid to show their PM that they have meds left over. If you don't want to bring the bottle, then it might be best to atleast tell them that you have some left over, but are still in need of the usual fill. This atleast lets them know that you aren't overusing them. If you have no meds left because you needed them all, keep it WELL DOCUMENTED in a pain journal. If for some reason, this PM screws you over, you have a written history that you can show to another doctor down the line.
This doctor seems atleast somewhat in tune to your condition otherwise hed probably be prescribing T3. Conditions severe enough to warrant morphine = a doctor should intristically understand that the patient is consistant at a level 8 pain or higher without the medication (6-7 for moderate to moderate severe, 4 to 5 for low moderate to moderate pain - which at levels 4 to 6 according to WHO should be treated with milder narcotics, and pain scale of 7+ should be treated with major narcotics).
MRI revealed a bulging disc w/gel lost at L5 and showed the bulge touching nerves, causing sciatica. Diagnosed w/ Arthritis which is responsible for joint inflamation pain. Treatment: Nucynta 50-150 mgs every 6 hours (schedule II narcotic, Mu Opoid agonist and NE reuptake inhibitor), Celebrex 100 mgs, Klonopin .5, Epidurals, Radio Freq nuerotomy (sept 8th, 2010)