im a liar and a loser and i hate myself

i had just recently finished my mid year exams.....my mum is very annoying bout how i hav 2 study all the time to get good marks.i hav been lying to her all the time saying i hav studied when i didnt even touch my books at all.i feel bad about this.should i just tell her i havnt been studying or just keep on lying to her about it?i love my mum but i just dont feel the motivation 2 go and study.plz i dont know wat i shuld do.....i dont want 2 lie but if i dont then she wuld b sad about me not trying my best..... in another cenario my group of frends met this other group of girls and our 2 groups started hanging out alot.i liked this girl but my frend also liked her 2.....but meanwhile the girl found out that we both liked her.then i told the girl and my frend that i wuld let my frend try 2 date her and stuff.i kept doin this and i made the girl feel really bad and like a toy bcoz we just kept passing her around.i dont feel very good and i think she lieks me but i think i dont like her anymore....i dont know if i liek her or not....she keeps on making me think she likes me and then the next second she givs me the impression that she dusnt.wat shuld i do?shuld i still let my frend go 4 her or do i just like ring out?and a few days ago i saw sum pictures of her frend and i thought she was pretty hot....am i a dikhed bcoz i like whoever i c?bcoz now i wanna hook up with the girls frend...i feel like a dik.....liking the frend of the girl i had just liked.....am i unforgivable or just selfish?i duno if i shuld still b liking the frend of the girl or shuld i not like her 2 b a bit moral in a sense.....i dont know..... plz help me