Hello Sir, I Have White Spot On My Forehead Due

Hello Sir, i have white spot on my forehead due to pimples. it is present since last 10 years. My face has a dark pigmentation due to pimples.But before has a fair skin as compared. I have loss my confidence. Please prescribe any best cream to vanish this critical problem & get a fair skin. AIIMS (Delhi) Junior Doctor prescribed me something like Sebonac gel , is this effective.

plz solve my querry.

Thanks a lot.