You're feeling better, good
Everybody feels like that. Don't worry about it, it'll pass. But you need to give yourself a boost. Try going with somebody to a nice place outside, or a walk during a sunset. Getting out is the best thing to do, and having fun. Feeling generally down is normal, I feel like that alot, and so have alot of others. It might be due to stress and what's going on in your life, and it could definatly be puberty and the hormones.
Don't worry about it, go out and get something to do, someone to talk to, or do whatever you're doing now (if it's helping) and you'll be great.