When doing an energy clearing, how can I avoid taking in the negative energies myself?

Hi, I did an energy clearing to a room in my apartment yesterday which had horrible sticky energy, bad chi, and was just plain gross. Today I am feeling absolutely horrible, light-headed/woozy, and a really bad cough as well as asthmatic symptoms.
I have noticed such effects before from doing space healings and even distant energy healings.
I haven't had any direct physical teachers other than books, do you have any advice as to how to avoid this in the future? Should I not do clearings during menstruation?