There is more to one stature than physical height. A diminutive father can still be a giant among men. What starts out as children looking up when they are small can stay as a figurative looking up to as children grow up if we have the right kind of dad.
How do you measure up? Are you responsible and kind? Are you strong and compassionate? Are you hard-working and selfless? Are you brave and resourceful? These can all be things that will add to your stature in the eyes of your children.
Also remember that the opposite is true. Even a tall, strong, man to be a person that no one looks up to. Those who are quick to coerce their children and spouse with physical force or anger, those who let others do the work, and those who are crude and mean can only be looked down on. You must decide what kind of father you want to be.