Benzoyl Peroxide skin damage

Patient: Hello. I am a 34 year old female and i recently (6 months ago) developed cystic acne. My dermatologist recommended erybenz, a medication containing benzoyl peroxide and told me to apply it all over my face.I only used it once but it seems i applied too much.It caused a burning sensation and after three weeks i am left with deep lines on my right cheek and a big patch of loose skin on my left skin, which makes me look 10years older. Any advice would be appreciated.