EWW, why do I have a huge green pimple?

green sounds like infection, not normal acne, call you doctor's office and see if he can see you today, if not check and see if you have some sort of prompt care center in your town and try them. If you can't be seen today, definitely go tomorrow, for now I would wash it gently and put an antibiotic ointment, don't pop it, that could spread any infection.