I am really Confused, Please Help?!

I am really Confused, Please Help?

ever since the begening of this year, i went to talk to a teacher that i am really close to know about my problems , i can be really happy, i achieve alot and think positive one day, then the next day i can feel like my world is coming to an end and i cant do anything right and i just feel like running away and i get really sad and i hide away in my bedroom and dont talk to anyone but then the next day i can be really happy again. please help whats happening to me?

See your doctor as soon as you can. You can be screened for depression/manic depression and get some real answers from real doctors, don't rely on what people on the Internet will tell you.
Good luck to you.