I needd your help really bed please please please please!!!?

I NEED HELP I WENT OT GO AND FEED MY DOGS THIS AFTERNOON AND I FOUND THAT ONE OF THE M HAD THIS HUGE RAW SPOT WHERE HE HAD SCRATCHED HIMSELF RAW. SO I WASHED THE AREA AND CUT TEH REMAINING HAIR FROM THE AREA AND SPAYED THE AREA WITH ANTISEPTIC TOWEL DRIED AND SPRAYED AGAIN. I PUT A PAIR OF MY BROTHER'S BRIEFS ON HIM BACKWARDS SO HIS TAIL COULD POKE OUT. SO HE CAN'T GET TO THE AREA ANY MORE. (OFF TO THE RIGHT OF THE BASE OF HIS TAIL). WHAT ELSE CAN I DO TO KEEP THE SORE FROM GETTING INFECTED??? I ALSO HAD SOME ANIT BIOTIC LYING AROUND FROM MY OTHER DOG'S SPAYS. AND SOME MILD PAIN RELIEVER THAT WAS LEFT OVER TOO. PLEASE I NEED SOME HELP