Thanks for writing here.
It seems you are having post acne hyperpigmentation
along with sensitive skin.
Sensitive skin is both oily and dry at the same time.
Use a good cleansing lotion like cetaphil
Avoid sun as far as possible.
Drink plenty of water and eat fresh fruits.
Get your hemoglobin
level and thyroid
Depigmenting creams have slow onset of action .Keep patience and continue with treatment.
Hope this will help you.Take care.