How to fade acne scars within a week?

Can't be done: Red and hyperpigmented lesions need to be allowed to fade on their own over several weeks -- trying to lighten them will just end up being more trouble. Depressed acne scars can't be managed except by a dermatologist of plastic surgeon, but results are pretty good. I'm sorry you ended up with scars and hope you are managing things so you don't get new lesions.

That's asking a lot: A hydroquinone bleach can fade the hyperpigmented spots after the acute lesions heal. Nothing you can do will touch true scars, but a physician with a laser, microsurgery or a filler can make them less conspicuous.