I too had many of the symptoms described above. Heart palpitations, increased back pain, muscle cramping, brain fog, fatigue and mood swings. I found that I was totally intolerant to calcium and it is in everything. Fruit, veges, water, as well as the usual dairy even brown rice and sesame seeds. I found that the only thing that helped me was to increase my magnesium to balance some of that out. That has worked for a year, but now the blood pressure is up, and I've developed and intolerance to sodium as well. Can't win. The magnesium that was the most helpful was "Calm" from Peter Gilliam available online or in health food stores. I noticed an immediate difference. Body aches and pains were alleviated when I started taking Vitamin D3 oil. Made a huge difference.
I'm stilling working on the calcium allergy issues. Western medicine says it's impossible - you can't be allergic because it is a necessary mineral - but you body can have an immune disorder and essentially see itself as an enemy. Show me the difference because I can't see it. Logic doesn't hold water. So as far as I'm concerned I have a calcium allergy and need to find a way to get the body to accept it again. Currently looking into "NAET" for a type of treatment.