I'm sorry Zero. Maybe opiates would help, but I don't think doctors would prescribe them, they would probably try metamizole which might help but it's too weak for a moderate/severe pain and obviously won't work on long term.
If a kind doctor would prescribe tramadol, it's already a start. I hope you manage to get some, might help you a lot.
Chronic pain is the worst. There are very little treatments available, even less when it's caused by a rare condition.