It sounds like you have long-standing Acne vulgaris and have already tried strong medicines like Isograce 20 and Zithic 500, so now you should avoid self-medication and focus on a steady routine: wash your face twice daily with a gentle cleanser, use a light non-oily moisturizer, and apply a topical gel with adapalene or benzoyl peroxide at night (only if prescribed), and always use sunscreen in the morning.