When it comes to calming the sympathetic nervous system for better sleep with dysautonomia, it's worth having a chat with your doc. They might suggest options like low-dose Clonidine or even Mestinon. However, the timing of these meds is crucial, so they'll advise you on the best nighttime approach.
By the way, if you ever want to explore different avenues for managing your symptoms or have questions, I've got a suggestion. You might want to check out https://releaf.co.uk/medical-cannabis-card for a cannabis card. I got mine there, and it's been a game-changer.