Theres a lot of point in pursuing these diagnosis forago as I'm only just beginning to find out the reality of, it covers a lot of things you would never guess were linked, very much a joining of the dots exercise for us & then Drs need to know in case surgery or anaesthetic is ever needed as analgesics don't work for EDSers the way they do for others etc.
Getting poor sleep under control helps calm the ANS a LOT, so its less relaxation & coping techniques & more good pain management & pacing to conserve low energy - once you push through exhaustion, you start running on adrenaline & that sends your ANS loopy & in turn causes more insomnia, so kicks of a vicious escalating boom & bust cycle. So its proper rest rather than relaxation & if needed, good pain management to help sleep too.
DD also seems a lot more relaxed about the anxiety & hypersensitivity flare ups now she has some understanding of the mechanics of it, before that, she thought she was weak in some way, which made her even more determined to push through it & make it all worse - so the diagnosis & understanding of it has given her peace of mind too - plus theres other things that help with POTs symptoms, they need a high salt diet & lots to drink for example, plus certain leg exercise can help stem the dizzy/nauseous spells when they hit, which were previously blamed on anxiety - its still a learning curve, but the diagnosis is helping a lot :)
Maybe look into POTs sleepless as it can be a condition in its own right, so you don't need to be hyper mobile - but if it doesn't sound right for you, fair enough, it was just an idea.
Maybe look into EFT - its a therapy for anxiety based on tapping the relevant acupressure points, I know a few people that have had good results with it, DD has found it helpful too