hi, thanks for posting your query
You seem to have postinflamatory pigmentation and scarring after the injury
For the same you may do as follows:
Undergo a few sessions of peels alternating with microdermabrasion
A cream containing hydroquinone
, tretinoin and hydrocortisone
at night for a few months
A sunscreen during the day .
oral antioxidants and vit C supplements
Take the above treatment under a dermatologist
as they may be associated with a few side effects.The response to these treatments is slow and require a lot of patience.
Hope this solves your query