Thanks for writing in.
The condition you are facing can be postinflmmatory pigmentation,amyloidosis lichen planus
Without actual visualisation of the skin it is not possible to comment on nature of pigmentation.
Sun protection is most important for any cosmetic treatment.
Use good quality sunscreen.
Avoid sun exposure.
Use brevoxyl face wash.
Apply depiwhite cream at night.
Take lot of vitamin C
Visit a dermatologist
for proper examination and diagnosis who can also provide you some clinic based procedure like chemical peeling and laser.
Hope this helps.