Find a Cognitive Behavioral Therapist CBT specialized in Chronic Pain. Anxiety is the same part of the brain that deals with the intensity of pain. The Bipolar is very heavily related the back pain and MP. Not the actual injury but how much it is hurting you. The brain actually rewires to be more sensitive to pain as well. Nerve block from MP is right at top of the hip bone just under the skin. If a injection of Lidocaine in the same place did not almost immediately relieve the pain to light touch, it is probably not MP.

Good luck! the calmer you can keep yourself with relaxing, meditation, swimming, yoga, tai-chi, etc.. the less the pain will hurt you. Mindfulness Meditation can actually teach you to acknowledge the pain, but observe it like it was a third party. Knowledge is a big part of the game

Rob.