Acne occurs due to a blockage of oil underneath the skin and builds up with bacteria causing inflammation and develops into a pimple. The common causes of acne are poor diet, stress, genetic, dirt, hormonal imbalances, cosmetics, work-related and drugs. Wash your face with mild soap many times a day. Avoid popping or scratching them. Drink plenty of water. Take a good sleep.Benzoyl peroxide is very effective for acne. You may need oral medications since you have severe acne. It is best to consult a dermatologist if symptoms are severe or persistent. I hope it helps. Kind regards.