Hi You seem to be having acne induced pigmentation. This is usually caused by a large acne or when you try to squeeze the acne. Please use a ph balanced salicylic acid face wash twice a day.use a broad spectrum sun screen regularly to prevent further pigmentation. chemical peels and lasers can help you reduce the pigmentation quite quickly. Please contact a dermatologist who can examine you and prescribe the appropriate skin care products as well as advise you on the treatment options