Can you tell me natural ways to get rid of an acne/pimple scar?

There aren't any: Depressed scars are permanent; red / brown marks fade in months. I'm really sorry you ended up with these lesions, and I hope it was not the result of a caregiver's preference for "natural remedies" over treatments that actually work. Get with your personal physician about managing your disease; if it's scarring, you'll need prescription-strength Rx.