Why are you feeling depressed now (just like me)?

I'm a teenager... so I'm just going through all the basic teenager stuff, you know? A lot of stress and drama and I'm always so anxious.. I have really low self-esteem and I'm in a relationship with a man that is about 20 years older than me and it's just a big mess. Sometimes I force myself to throw up or sometimes I cut because it makes the pain go away for a little bit... but I'm sure it'll all p in time. If you ever need to talk, you can e-mail me :) I'm usually the person my friends come to for advice, no one knows what I really feel because I'm the "funny one that is always smiling"..