Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain 
hyperpigmentation can occur due to a number of causes like sun tanning due to excess exposure, exposure t heat and chemical fumes, stress, malnutrition, hormonal imbalances etc..
I would suggest you to start apply safer and effective 
depigmentation creams but you should keep one thing in mind that you will have to take a continuous and long term treatment.
You can start washing your face with 
Salicylic acid and 
glycolic acid containing facewash..
Apply creams containing Kojic acid, glycolic acid and arbutin..
You can also apply Vitamin E and C containing creams..
You can exfoliate your skin twice a week..
Always apply sunscreen lotion when exposed to sun..
Drink plenty of water and take a nutritious diet..
You can also go for treatments like 
Microdermabrasion and chemical peeling.
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.