Suggest Remedy To Lighten Dark Round Spot On Face

hello sir

I got a cut on my face while shaving. To stop blood I put dettol soaked cotton on that portion for about 10 minutes. After that a dark round sport has appeared on the portion of face where I had put the dettol soaked cotton. It looks like a burn and has burning sensation too. Please help me out to get rid of this dark spot.
Thanks in advance
Narendra