All day i get really peed off at everything and im so depressed and upset, it might be because all my friends are at school and i have 2 weeks off and the only time i talk to them is at night, i dont know, but im so lively and active at night with a big smile on my face :D i dont know what causes this?

One might simply be your environment. The boring stuff happens in the day, and the fun stuff at night.
Another is your 'chronotype', this is simply being an evening or a morning person. Sleep in and stay up late if you can get away with it for max good mood :)
Or, there is diurnal variation, which is a common symptom of depression. Which is you feel very crap in the morning, but slightly less crap in the evening.
More information: http://www.beyondblue.org.au/index.aspx?link_id=89.1196