You seem to be omitting reversible cryopreservation from the scenario. All you would need to do is freeze yourself until a cure is found for whatever is causing

You seem to be omitting reversible cryopreservation from the scenario. All you would need to do is freeze yourself until a cure is found for whatever is causing you pain. But this seems like a non-likely thought experiment scenario anyway -- I can't imagine being able to regenerate body parts and prevent aging from being lethal, yet being unable to comprehensively prevent pain.