No one is perfect, we all have flaws and weaknesses -BUT there is great potential in everyone. Even a person with limited brain-power or talents has something special. That we are all capable of loving and caring is in itself a very special thing.
The big problem is - if you hate yourself, this the rubs off on other people. There is tendency to see in others (rightly or wrongly) the things that you hate about yourself.
One marvellous thing about being a Christian is that you learn how God sees us -he sees us with a loving eye for he knows the talents and characteristics for good and attractiveness that reside in each person, our job is to humbly cultivate these positive traits and features.
There is also the tendency for utter selfishness and even cruelty and depravity, the secret is to make a sound decision to live life to our best and be kind, especially to those who struggle in some way, or are going through a bad patch -like bereavement.
It sounds like your early experiences have been negative and have led to psychological damage, your not growing in confidence and not performing at your best is NOT your fault, neither is their some deep lack within you; we all need good encouragement when young, if we get nothing but punishment or insults we do not thrive . Do not let these negative things shape you, come out of this like a snake casts its old skin and becomes renewed. Ask Christ into your life and he will start to rebuild you into being your REAL self! To know that there is a wonderful reason and purpose for your life is heart-warming!
God bless and guide you into personal fulfilment! - And faith in your Heavenly Father and Friend.