It's really good that you are seeking help and you are aware of your situation....most of the time, people ignore and deny their problems....
You are so young to go through depression...I am suspicious that you may have hormonal changes in your body....I'm not a doctor, but our brain and body has been govern by all these Chemicals in our body....
However, the good news is that you can help yourself and get out of the depression and sadness....
here is some recommendation which helps me day to day and I wish I knew this secret ingredients when I was at your age....
1. have faith...any kind....faith will warm of your heart and make you stronger...
2. meditate and pray....try to learn meditation, you can either read about it or take a class....You can start with just 5 minutes meditation....
3. Keep in your mind that past and future don't really exist, stay in present moment....we usually think about what has gone wrong in past and we are worry about the future....and funny thing is that, past has gone and we can't do anything about it...also, future hasn't been happened yet and we don't know if even it will happen!!!!
4. exercise....be as active as possible, then you can get connected with positive energetic people
5. see if you like dancing, you can go to dance classes....but you should be strong and persistent....
6. read aspiring books and quotes....somebody at this site recommended me this website
http://www.happinessinthisworld.com/ it's awesome...read it...
7. each time you feel you want to drink beer, then replace it with fruit or exercise....then you feel proud of yourself for overcoming something that cause you addiction
8. take one day at a time....slowly...
9. think about funny stuff that has happened in your life and laugh about them again and again...even think about the misfortunes and laugh...they are like a movies!
10. don't give up....you got to try everything to find the one that is good for you....
we always try to find happiness outside of ourselves...but happiness is within us....I personally found out if I'm not happy and comfortable with myself, if even I am in a relationship or between thousands of people, still I feel so lonely....
take care of yourself and tell us when you feel better
we are here for you
with love
Marjan