Just on the salt front, I take 3g of salt (in tablet form) a day plus pretty heavily salting my foods. I think this helps. I can usually gauge whether I'm getting too much salt (rarely) by how it tastes to me, if it tastes good = then I'm not over doing it, if it starts tasting bad = I cut back a bit (again, this has only happened a couple of times). There's no way I could get enough salt just via food, I have to use the tablets.
No real ideas on calming down, I haven't gotten the adrenaline/wired/tired stuff in a while and I think even when I did I didn't have a ready remedy. Reducing stimulation (sound/light) makes sense, but I also vaguely remember watching a lot of formulaic familiar tv on netflix (on my phone, in bed, in the dark) or formulaic familiar books on tape and I found this soothing, I guess because it distracted me from some of the unpleasant body sensations? Good luck!