For long-term, severe pain, really your best bet will probably be a progressive pain control specialist. They can help you figure out long-term strategies that can be helpful.
Stuff like TENS units, physical therapy, trigger points, accupuncture, etc. can sometimes be helpful, depending on the cause of your pain.
Progressive pain specialists won't just dope you up on drugs for long-term issues. They'll try to do what they can to get to the root of the problem as much as possible.
Otherwise, depending on where your pain is, you could always see a specialist for that area (OB/GYN, GI, etc.), and explain your concerns about being doped up.
I sure do wish you the best. Chronic pain is no picnic!!