What to do when you feel depressed, and like life sucks, and you have nothing to look forward to?

maybe its just a passing mood or something.. but i just feel like my life is lame and sucky. i dont have very many friends, almost never do anything with the few i have, i mostly just stay at home and watch tv, or go on the computer, and sometimes workout and play basketball and go jogging. sometimes i play basketball with my friends, or go out for food, or have youth group at my church, but thats about all i ever do.
i feel like i have nothing to look forward to, nothing exciting in the future. sure, ill graduate high school, maybe go to college or university, get a job, but then what? just go to work and probly go home and do nothing like i do now? maybe get lucky and find a gf, but i somehow feel like i probly wont, and will end up just being a loser at home, doing nothing, with no friends, and no life. sometimes i wonder what it would be like, if i was more popular, and went to parties and hung out with people and actually did stuff, and it seems great and alot of fun, but i just dont have many friends. the friends i do have, im barely even friends with them, barely do anything with them, talk to them at school every once in a while but thats about it. the only thing i see in the future, is going to heaven, which will be wonderful, but i still have a whole life time before that, heck im only 16, i still have tons of things to do before i die. maybe i need some goals for the future but i dont really see anything.. just a job after high school, making money to pay for a house and stuff, then retiring when im old.
ive never even had a gf, only ever knew a few girls, got a phone number from one once, who was pretty cool and nice n stuff, and i liked her, and phoned her a few times and we talked for a while, but we only got a hold of eachother a few times, then no more phone calls and we never even met up and went to a movie or out for dinner or anything.

sorry, kinda long. lol. just a rant for the mood im feeling right now i guess. what can i do to cheer up and make myself feel better and like ive got a good life (which i kinda do, live in a decent family, were not too poor, and im doing alright in school) and like i will have a future, and not just be some loser sitting at home then going to work, then home, and nothing else.. help me