Need help ASAP about my boob

So just 2/3 days ago I seen this circular dry pack located next to my areola. It’s dry and I’m not sure what this is from. I’ve never had this problem. I looked it up and the last picture was the only thing I found and it doesn’t give me a clue. Doesn’t anyone know what is going on? Please and thank you. I’m trying so hard not to overreact but I’m nervously scared.