I feel very apathetic and depressed..help?

the PSAT is this wednesday and i just looked at a practice test, and i can't remmeber certain things...i think it is a result of my apathetic state. lately i've been so careless or frustrated...two extremes i know, but that is how i feel now. i constantly think about life, is it worth it? or why is it so boring...i find it boring...i am not interested in making new friends...and i neglect my hw sometimes...and just sit, walk around...i really hate this state, i had this last year too but then it stopped. this one is taking a longer time now..i don't know why...im constantly bored and dream of doing something like going somewhere windy, cool, and crazy...like out in the open gry plain by cliffs and the sea where i would run free and act like a small child again. I also don't want to participate in many things at all...just don't want to at all...like before i was a christmas fanatic when i was small and now i don't care. i have this heavy feeling in me which slows me down...help plz?