Cold sore, canker sore? HELP PLEASE.?

i'm not sure what i have. but i was at my orthodontist 2 days ago, and they gave me a banana spray. that night i went to sleep and woke up with these two white things on each of the corners on my lips. its inside but its right on the corner. i can barely open my mouth, and it hurts really bad. everyday it seems to be getting worst. i was wondering if someone knew what is it, and how to treat it? thanks to everyone who helps:)