Depressed and thing of ending life everything is crap girlfriend cheated on me and im only 16..?

[Sam]

I started getting depressed about a year and a half ago after my girlfriend cheated on me. I loved her i always wanted to be with her but she always pushed me away when we went out for about a couple of months and i knew something was wrong at school she didn't like being with me at home or out she always holded my hand and hug me and was totally different then at school a girl tryed to tell me at school she will cheat on me she does on all her bf shes had i didnt know her past i knew her but not that well. But i didn't belive the girl i thought she was trying to split us up and i trusted my gf. But in the end my gf friend told me she was cheating on me i had a go at her for not telling me because she was my friend aswell my gf friend and she fell out with me and i split up with my gf ...... I didnt want to but she would of cheated on me again. we split up and i miss her all the time i dont know what to do i started smoking for about half a year the school told my mum beacuse they saw me before school smoking this was last year of school and i finished after exams and mum made me stop smoking and now wont let me go out even though im 16 and i pushed most of my friends away im not aloud to go out cause my mum doesnt want me smoking i dont have a job because i didnt get good gcses my family calls me dumb and stuff they say i must of been a mistake because im nothing like them and i just had enoth now and im thinking of ending it all. So i dont no what to do i have nobody and nobody wants me my life ****. i still talk to some of my friends on Facebook i didnt tell any of my freinds she cheated on me because i dont like talking baout it. I dont know what to do anymore im 16 i might just end it all.