Why am I so weird please help?

idk if am going insane or just really immature. Ok im a really shy person but yet I love attention. And sometimes am not shy..like i have multiple personalities. I change the way I feel about people everyday like one day ill say i flipping hate that bit*h i hope she dies and the next day ill be like omg i love with her with all my heart. Im always day dreaming..I laugh when people get really mad and break things..i actually find it hilarious. Im very nice, like i never would want to make any one feel bad, but yet im mean to ppl like in a way to push them away from me. I feel like killing myself sometimes and get so depressed and the next day illl be the happiest girl ever always smiling and in a positive mood. I think im bipolar but idk like im so weird...I am starting to creep myself out. I kno this isnt normal. Also one day I will feel beatiful and act super conceited and the next day i will feel ugly like if i am seeing a different person in the mirror and id want to kill myself. Im always laughing when people get mad..I talk really fast...im really sensitive..Im always thinking and thinking and like i said day dreaming..and i care a lot about what people think. Also i find things funny that other ppl will not find funny. So what is wrong with me? Are these symptoms of insanity or am i just bipolar idk its just really bothering me a lot:( i just want to be normal. btw am a 17 year old girl that went thru a horrifying childhood if that helps..thank u anyhelp is appreciated and please do not leave rude comments :( thank u