Is it normal that i feel like i scratch off my skin?

Whever i scratch my skin, it feels like I scratched off all of the skin and muscle. So, i always have to go back to the same spot and 'undo' the scratches by tapping my hand and fingers on the spot repeatedly for about 45 seconds. If i dont do this, i get really fidgety and cannot focus on anything at all except the fact that my brain thinks i have deep scratches on myself. Is this normal ?