Yes, sounds like RSI. If it is it can only get worse.

When I was still in H&S I used to suggest trying a trackball. It sometimes helps.

Try to get one with a central ball, rather than a thumb operated one.

I don't know about Electromagnetic hypersensitivity,but there as been quite a bit of discussions on the subject. But one thing I do know, is damaged nerves and how that can effect some daily activities.

A number of years ago, I had a minor motorcycle accident, which according to an A&E consultant at the time, stated "nothing seriously wrong- a bit of possible bruising- take paracetamol and rest - everything should be fine in a few days". That man could not have been further from the truth, things turned out far worse, with the end results of operations or the choice of various operations.

One part was the finding of nerve damage, and after further tests I was given the option of an operation or let nature takes its own action. It was clearly stated, the operation would have resulted in 'improvements, nothing or possible lack of future body movement and functions, or even death". I chose "let nature take control", but some days I still wonder if that was the right or wrong decision, when 'tingly' comes into being, and anything I touch doesn't seem real. Even catching the back of your hand on a hot cooker mesh sometimes doesn't show emotions, because it isn't until later, that you realise what you have done?.

What can be said though, there are some tests available, similar like accupuncture, where a number of needles are inserted in the body at various points, and 'electric readings' are taken and recorded. Apparently, when I had my tests done, the team conducting the test said that I had "hit the jackpot", whatever that meant. I didn't bother to find out, perhaps I should have?.