Im so fed up with my life, i just want to die?

Im almost 16 now, an my life to most people i bet they would think is great, but i dont know what is wrong with me anymore and i wont ever admitt to myself i may have some form of depression. I was always really happy and in a general good mood until this year started, it just got worse an worse. My whole family and a group of friends used to go on holidays together ( all the parents were so close and us kids grew up together) one of the older kids, a girl, jess, she was 17 and died, she got hit by a car in january, none of us ever speak anymore and it crushed us all. As many of us are getting on with our lives, i lost my virginity in feburary and got in a serious , lasting relationship with a really nice guy, my family liked him and he lived closed by, we were so close, but he ended it out of nothing months later and admitted months after the breakup he just " used" me. That to me was so damaging, he was someone i trusted and shared many memories with and the fact i lost my virginity with him, really upset me. Its coming to the time when i have to p my exams now, its my last chance, and im struggling, i cant p my maths no matter how hard i try and i need it, teachers are giving me such a hard time. My family are always argueing and blame me for everything and think im so "spoilt" when they just dont understand, i really am having the worst time of my life. My grandad is dying of cancer very slowly and my best friend has become bullimic and turned her back on me. I pray sometimes, and somehow it just get worse. This will sound stupid, but EVERYTHING breaks on me and it feels like a curse, ill save up money to buy a dress for example and then ill find a whole in it the next day. All my valued items just break on me, my laptop, phone? and i dont know why ! People genrally just stress me out with their constant judgements and immature behaviour in my school, they are such snobs and i feell i am trying SO SO SO hard all the time and i am never going to make it ! The stress from everything is also making me eat junk and binge, and not sleep well, so im looking worse than ever, skin, weight, eye bags. I cry alot, and always say, " ive been in times like this before, and i've come out fine" which i have , im just waiting for it all to end and for it to get better, but it drags on and on ! and i fear this time it wont...