Hi, You said that you have acne vulgaris and post acne hypermelanosis. First of all, acne lesions should be controlled as acne is a recurring condition. Please avoid anxiety related with acne. And please avoid precipitating factors like stress,oily food,dandruff,excessive sun exposure,drugs like steroids...etc You consult dermatologist for firm diagnosis and firm treatment. You take antibiotic like minocycline or azithromycine in proper doses along with low dose of isotretinoin. And apply clindamycine gel on lesions. After control of lesions, you may apply depigmenting cream containing kojic acid. Cleanse the face with facewash containing kojic acid and glycolic acid. I hope you may feel better after few months treatment. I hope you got my answer. Thanks. Dr. Ilyas patel MD