I know how pressure at school can suddenly collapse onto you. I have experienced certain periods in my school life in which the daunting prospect of exam failure or friendships on the rocks has caved in on my conscience, at as a result, my grades dipped below my personal standards. Thankfully, it has yet to wind me up in trouble, but I can empathise with your lines of thinking, at least.

Sometimes I think it can be a lot to do with age. This period in our lives, which ultimately shapes the rest of it career-wise and socially, is so focused on achievement, and yet ironically is also the supposed 'great age' of having fun and relishing one's growing independence. The emotions experienced from one day to the next as an adolescent can be confusing to say the least.

I know from personal experience that goings-on at home reflect my school behaviour more strongly than something that actually happens in school itself. Of course, I do not know your family relationship situation, but I thought it may be worth a mention.

My advice would be to get your head down, and stay at school. Perhaps, if there is a teacher that you particularly like and would feel at ease talking to on a personal level, arrange to have talks after school or during breaks about how everything's going. It may sound pointless, but it is a real help. Not to go into too much detail here, but I have a friend who had quite a serious emotional problem that stemmed from family and friend relationships and fear of under-achievement. A group of friends and myself organised with a teacher we trusted to have one-to-one chats with him, and it helped wonders. This friend still occasionally has issues, yet he is far more positive and motivated than he ever was before hand.

I wish you the best of luck. ((hugs))