Coming from a dude with a very similar size, let me just say there is nothing really skinny about a 5" girth. Is it average? Pretty Much. Huge? No, but it aint small. Especially when your dick is long. I know being long makes it look even skinnier. But being 8x5 is bigger than 6x5. That said Im trying to get to about 9x6, and if any chick were to tell me that aint big, I'll fuck her hard til she bleeds and then ask her again.
There a lot of sub 5" girth guys out there that arent really considered small, so I'm happy at least being in the 5s.