Not OP but similar story with someone I know. Five years of many specialists that always ended in "all the tests are negative so it must either be fibromyalgia or psychological." Doctors never helped but eventually they empirically found that abilify and rexulti in very low doses (ie: half the minimum) made it just go away. Empirically based on the reaction to various medications it was probably some type of dopamine imbalance or issue. There's other case studies of similar reactions to abilify and chronic pain but not many.

Extra fun fact, a deep research AI nowadays will actually suggest this as one of the treatments given a few paragraphs of information on the symptoms/medications tried/etc.