How To Treat A Bump Behind The Left Ear?

hi i have a bump behind my left ear, and its down by my lobe, in the soft spot between your skull and jaw. its not painful, and its not getting bigger, but i am a total hypochondriac, and i think i have brain cancer now. any tips? since it isn't painful, i don't know why i'm freaking out. i also have two lobe piercings, and i just got an industrial piercing in that ear two weeks ago. that means a bar going through two cartilidge piercings, and it isn't healed, so i don't believe it is a keloid scar. i am also very stressed out, and have been sick for the last few days, but i have had the bump atleast two weeks i have noticed. a long while before i've been sick. thank you!