You may be able to shield part of the wall, unless the place is some sort of open office.
The radiation goes pretty much in a straight line, apart from reflections, which make the thing tricky, and other issues.
However there's emf everywhere, from monitors, routers even with wifi disabled, adsl-cables, electrical wires, mice and keyboards, mobile and dect phones, fluorescent and led lamps, smart-meters, light-dimmers, and what else.
So the first thing seems to be to eat healthy ( in my view : no meat, no sugar, no bread, lots of fruits and vegetables, preferable raw, and enough water but not during meals ), sleep well ( early ) and in a low emf and low mold environment.
This means of course no fl-s or led-s, microwave-oven, wireless shit in the house and no wires near the bed, nor dect or wifi from neighbours, nor cell- or broadcast-towers, no synthetic surfaces and open windows.
Then avoid exposure to strongest unnatural fields, so never use mobile or dect phones except on the speaker-phone at a distance of two meter or more.
Third, sit back when behind a monitor and do not do this to get lost but only on purpose, as little as possible.
Personally i carry a gimmick called "bioprotect"-card that seems to help somehow and is cheap, which you may openly or secretly shove into that damned router, especially after having a similar experience with it while wearing it.
Perhaps these recommendations are all nothing new for you, in that case someone else may still appreciate this simple-minded response here, so i'll push the "post" button anyway.