I feel sick.

The simple explantion is: You're a Teenager.

I have felt this way many times before but i always cheered myself up によって doing the things i like most like for instance listening to Vocaloid songs.You should also try doing the things あなた like most, it might cheer あなた up.
によって the way the song below always gets my spirits up,and maybe it might do the same for you.

I know just the thing!

has anthing bad just happend? that might be y. または maybe u just feel like that. i have those days once in a while. it'll be okay. u will probably feel better tomorrow. if not u can talk to me. ur not alone.

Do a hobby, talk to your フレンズ または family, watch something funny on Youtube...
Do something to make あなた feel better または to express yourself.

あなた has a chemical imbalance in your brain meats. Go to your family's doctor, and he should give あなた a pill that will fix it. The most important thing is to keep yourself busy and stay around friend and family.

i feel like that sometimes.
listen to an owl city song. that always make me happy (:

i feel the same now for 5 weeks now... so i need help, too.

yeah, i usually call または hangout with my friends. some how it makes me happy. :)

Yes,I've suffered ,and I went to doctor , he gave me some medicines ,and I get better each day!!!1

Es una parte de la vida
:P