Like another poster said, mold is something I would investigate.
Electromagnetic hypersensitivity is something I just recently uncovered and know hardly anything about it, except that a large number of people seem to be very sensitive to EMF waves from WiFi, cell phones, etc. This could explain why the jungle seems to treat you so well. Seems crazy I know, but check out this thread: http://forums.phoenixrising.me/index.php?threads/the-electrical-apocalypse-can-we-avoid-it.26545/
This gives a new perspective on the stereotype of the tin foil hat wearing conspiracy theorist, lol.