I am sorry to hear about your pain and your non diagnosis...Yes, it does take time to get into a good pain management doctor. I waited 2 months. I have found there are not a great deal of pm doctors and the wait seems to reflect this. Also, I would imagine it would depend on the state in which you live in.
It definately sounds like you need to have a thorough exam done by pm specialtist. I do not have your symptoms, but, they do not sound like 'just a back ache.' Its your boby and your pain and one must be relentless in pursuing a diagnosis and pain managment if needed. When it comes to finding a good pm doctor one must be determined and do not take no until a dr. can diagnos your condition and can properly treat your pain.
Yes, there are other medications besides norco. For starters, there is a generic to Norco - hydrocodone 10/325. It is about half the costs of buying the name brand Norco. There is also oxycodone 10/325 which might be worth switching to for the time being due to you developing a tolerance to the hydrocodone.
I wish you the best,