What Causes Formation Of Blisters With Darkening Of Skin On The Burnt Hand?

Hi , I burned my wrist with a pot cover yesterday. I immediately wash under running water & used two ice cubes to cool the area as it was trobbing & painful. After tat I dried the area & apply white toothpaste thickly over the area for abt 4hrs before showering. After that I dried the area & apply aloe vera gel & went to bed. This morning when I awoke, I noticed small blisters forming & by afternoon it has become a big blister & the skin at my wrist has darkened. I have just applied drapolene cream as suggested by a friend who swears by it. It's quite painful. I do not wish to have scarring. Please help!!!!!!!!!!