It's good you don't have Addison's. It sounds like the the responsible genetic mutation(s) is/are already clear. I hope your doctors are able to identify some sort of gene therapy or protein replacement therapy that could correct or replace your mutant SDHB (and any other mutant genes) so you can get some relief. FYI, my mutant SDHB is hereditary and, together with another mutant gene FBXL4, is responsible for my peripheral neuropathy and Addison's (and possibly my seizures). But every case is different, and treatment seems to require a custom-made approach. Praying for a good outcome for you.