If you haven't already told your parent, please do so they can monitor it for infection.
What type of earring are you attempting to wear? When I had my ears first pierced I tried wearing some of the cheaper fashion earrings and constantly had a bad infection from them no matter how much alcohol I used. I started wearing nothing but 14k gold earrings, not gold plated, and the infections went away.
My body must have an odd chemistry. I am unable to wear metal watches either. In just a few weeks, all the metal plating on the band and back of the watch gets completely removed. Had to switch to leather or plastic bands and coat the back of the watch with clear nail polish.