What Is The Treatment For A Dark Skin On The Face?

i am 22year old boy.i have a skin problem on the face.that's because 2 years back i have put a fairness cream .and it made a negative reaction .the portion which i put the cream became dark and dull .there is small acens on that .when i press on it.a small amount of semifluid puss comes out.please give me a solution to make clear my face