Unfortunately, no, there are no laws on your side except that you have a legal right to your medical records. They absolutely cannot be withheld from you.

No doctor has to treat you other than in an actual emergency. You might be able to find a "pill mill" that gives opiates to everyone, if and only if you have absolutely no history of substance abuse or anything in your medical records that might throw up red flags with the FDA, including abnormally high doses of medications. If you are on the high end of normal dosages, or you don't have a referral from another physician, it's unlikely that even they will take you, because they are the last practices that can stand any scrutiny at all.

It is, however, possible for people with chronic pain to find treatment. You say that you have a pain management physician, so obviously you have some treatment. I have chronic pain issues, and while I'm not entirely happy with the treatment I've found, I haven't had a problem with finding doctors who will accept me as a patient. (Caveat: I live in Atlanta, Georgia, where there are many, many physicians of every imaginable specialty!)

Have you ever read Full Catastrophe Living by Jon Kabat-Zinn? I recommend it (it's also available as a good audiobook). It's available from most libraries, too. Kabat-Zinn's approach is used in many multi-disciplinary pain treatment centers to help people learn to cope with pain.

Have you applied for disability? While it may be difficult to get a lawyer otherwise, it isn't usually difficult to find a lawyer willing to take a disability case, and they would then help you get your medical records.