My dermatologist recommended that I apply Benzamycin to cure mold/moderate acne. Four days ago, I applied a small amount on my face and the next day my face was fine. I didn't apply any on the next day. I applied a bit two days ago at night, and when I woke up and my face was red, dry, and itchy. I haven't applied any since then, but my face has remained red and itchy. Then when I came home today evening I saw that there is a very dark red/purplish mark on each side of my face along the jawline/neck. I was shocked because they look almost like huge bloody scars. These marks aren't bumpy or painful, just very dark.
What can I do to treat these marks and the redness/itchiness on the rest of my face? Will it get worse? How long will it take to recover??