You have what is known as PIH or post inflammatory hyperpigmentation. 1. Sunscreen and sunprotection- this forms the absolute cornerstone of management. You need to be on this for the duration of any treatment . 2. Apply a kojic acid cream for at least 8 weeks. 3. Chemical peels such as glycolic acid can help. You will need 4-7 treatments over the next few months. 4. Vitamin A such as tretinoin can help. The best treatment is a combination of the above.