I'm 12 and fail at everything i do?

I don't have good grades, i'm not smart either, i always lose when in a competition, i have a little brother that is a newborn and my mom and dad loves him more than me, i can't say anything, also my mom and dad spend time with him for hours and hours, when they come to me, will always be a yell or some thing to embar me, i'm ugly, i have a front teeth sticking out, i used to play guitar and wish to play the fingerstyle guitar like Sungha Jung ( my idol ), i can't even play 1 fingerstyle song, can't even learn half of the song, i don't have a guitar teacher, i fail at guitar badly i stop playing. later i started to like Kungfu ( Jeet kune do ) i am also a fan of bruce lee, i wanted to learn kung fu but my family can't afford me to go to China to learn martial art. i failed at it again. i'm not smart, everyone loves my brother and care about him more than me, i pray to God everynight that i can soon come to China and learn martial art, and pray my family can be healthy and happy, i pray that i will become rich then i can do everything i want, i pray that i can learn fingerstyle guitar soon, i pray everynight but it seem that God doesnt response to me or help me, i cry every night and try to hide from everybody, i fail at my looks, then i try to learn Kung fu online, everything fail again, i am a extremely weak person, i can't even do leg splits or kick correctly, i feel that i fail at everything in life, please help me, and i am very sorry about leaving a detail so long, i need help, thank you.