The best advice I can give you as far as this is, it's honestly pointless comparing yourself to other people. Most of the time you are comparing yourself to a false view of a person rather than the reality of them and if you already have a penchant for being down on yourself, you are most likely subconsciously inflating the greatness of the person you are comparing yourself to. Trying to compare yourself to an unrealistic and false idealized image of someone else will always result in you coming up short.
The only comparison you should be making is the you that currently exists and the you that you want to become.
I'll leave you with a humbling thought that hopefully provides some perspective. Even the most beautiful, most glamorous, most idolized person in the world still goes poop.