Where do you go when after 15 years and having changed countless meds, the meds are ineffective?

I have been on meds for years... when I started I was on Duragesic 75mg, norco (10/d) Zanaflex (4/d). I have tried Ultram, vicodin, skelaxin, soma, darvocet, nurontin, methadone, arthrotec, oxycontin....I have had pain injections and RF to the facet joint in my lumbar spine.  Now I have been at least maintaining the last 4 years on Darvocet...only not anymore.... heck at this point just maintaining would feel great right now....

I am at the point that I feel like I have a boulder pushing into my low back and no amount of meds are helping. I finally am able to get into my doc this tuesday, but I don't even know what direction to go!

Any advice???