Benzoyl peroxide irritated my face and left the applied area with darkened and damaged skin tone as if sunburned. its been few months and i can still see the difference of it from the surrounding skin tone. what can i do and will it heal on its own ?

Should heal in time: Some will have this effect if left on for longer than their skin will tolerate. Skin tone is created by pigment producing cells within the skin and can take a year or so to even out after a simple injury. There are no products that would speed this process but a sunblock could reduce part of the difference caused by sun tan on unaffected skin.