I hear ya! I went to the doctor with palpitations that were related to my crazy hormones around my period. My doctor said that they were "normal and a lot of women have them". She is a woman doctor too!
I started exercising and the palpitations have all but gone away. If my period is late one month, I tend to get them a little bit. (I have concluded, on my own, that it is because of a build-up of hormones in my body.)
I know they really suck. Sometimes I even need to cough really hard to get my heart going again. I know. But it works. My doc suggested this to my daughter for her palpitations.
Also, sugar tends to make them worse in me. It is good you identified salt in your diet doing it to you. The anxiety probably isn't helping either...
What can you do (that you aren't doing) that will make you feel in control of your health? Doing that thing will help with the palpitations and the anxiety. At least from my personal experience anyway...
Good luck to you, S.!