My penis size seems pretty small.?

hey everyone, i am a 19 year old guy. my penis is 5.5 inches in length and about 4.5 inches in girth. i know this is the average but it still seems pretty small when i look at it. my cousin says he is honestly 9 inches and my brother says 7 inches. i dont mind the size much when it comes to myself because for me it doesn't matter. i dont want to have sex until i am married, i want to save it for my wife. my worry is because i am afraid i cannot please my future wife. i want to provide for her and give her alot of pleasure but i feel like i am on the small side and i know if i have a loving wife then she will be happy but i still want to provide that pleasure for her. how can a 5 inch penis with a 4.5 inch girth have the same feeling as a 7 or 9 inch?