Dear m123, this is a very good question and area of investigation that everyone, not only those affected by electrical hypersensitivity, should probably be paying more attention to. My go to websites and organisations in this area are Powerwatch and Mast Sanity.
Although without researching this further I can't give a simple answer to your question myself, I'd like to suggest a few things:
1. It seems that EMFs emitted by the body would naturally vary depending on a whole range of factors such as general health status, hormonal and neurotransmitter balance, mood and associated CNS and ANS electrical activity, waking and sleeping states etc. Many diagnostic and therapeutic tools work in this area such as biofeedback - and recent developments of such. It may be worth you having a session with an experienced practitioner...
2. You reminded me of a book I read over a decade ago that it is truly eye-opening; The Field by Lynne McTaggart. Its central premise is investigating the solid science showing that each individual cell (whether human, animal, plant) has its own unique electromagnetic signature. This, it turns out can be amplified and encouraged to flourish, thus improving the health of the organism of which it is a part, or, it can be interfered with by electrosmog and rogue EMFs that modern human civilization emits from our various technologies; the result being electrical hypersensitivity and other environmental illness. In addition, this book provides scientific evidence that all cells are connected, regardless of distance (a la quantum field theory), and influenced by consciousness. It gets rather spiritual as you can imagine, but this is only as a result of where the cutting edge science takes things; it begins as an investigation of electromagnetic emissions at the cellular level.
I suspect you may find the above of some interest and would love to hear back from you on the subject, We can often get very dry and conventional in terms of scientific endeavor here at EiR and it would be great to push the boundaries a little!
If you are going through hell, keep going - Winston Churchill