Am I depressed?? Please read and help?

Things I used to think were fun are no longer fun. Examples, I don't like to play xbox anymore it annoys me, texting gets under my skin, I don't want to play guitar, I don't want to goto school( I used to love school I have no intrest anymore), I don't want to watch tv or movies, I don't want to hang out anymore. I have been having a lot of nightmares lately for about a month, I haven't been eating, I always feel like I'm tierd of whatever I'm doing. And so on