i want to get it over with

[i]"i hate myself, everyone hate me, this sucks"[/i]

You hate yourself because you don't know yourself well enough.
Try as many things as you can - you will learn new sides of you and will end up loving at least some parts of yourself. Eventually, you'll realize we are all mixed with different traits and so far no person is perfect, but you can aim to be the best version of you... which is farther than "perfect", because it means you are thrice more effortful than someone who has it all fall from the sky (myth).

I am certain that "everyone" does NOT hate you. You don't see the people who may like you because you are too busy beating yourself up with our own self-hating statements - I am certain there are wonders in every single person. Yours are probably just waiting for you to see them and develop them.

[i]"I feel awful"[/i]
Every emotion is ok. It is there to show you something. [b][i]Why [/i][/b]do you feel awful? Answer this question exactly, specifically, every single reason. Generalizations are not answers, you need your specifics to solve what you can and let go of what you can't.

"[i]when will i stop being a selfish brat that craves attention[/i]"

Wanting to feel cared for and liking to receive affection are not selfish. Maybe think of ways to project to others the same care you would like to receive. Some people will just pass you by but others will appreciate and give back threefold.

I wish you THE BEST

No need to hate yourself. Give yourself a break.

Ask yourself different questions.