If you criticize others for doing certain specific things then YOU do them too only MUCH MORE OFTEN why should we believe anything you say?

All things being equal this is true. Though things are often not equal. Sometimes the two parties are different, and therefore can be justly treated differently. 

A double standard is when someone claims the two parties are equal and should therefore be treated equally, but then fails to be evenhanded. If one doesn't believe in equality between the two parties, there is no double standard when we treat them differently.

For example, most people would criticise a man for assaulting a woman, more than a woman for assaulting a man. There is no double standard because we don't believe men and women to stand as equals in physical combat.

It is stupid to think that groups such as men and women, adults and children, old people and young people, rich and poor etc etc, can ever be treated the same.

Thomas Jefferson, paraphrasing Aristotle, said “There is nothing more unequal than the equal treatment of unequal people.”