How I Get Depressed

Every now and again, I feel happy and contented with life, and then one thing can happen (something can be said or done) and then I get all depressed. The happiness in my life seems to hang in the balance. I have extremely low self-esteem and when I go home, after a day at work or college, I begin to feel depressed unless I am doing anything. There have been a couple of times where I have just wanted to end it all but just couldn't bring myself to do it. What is wrong with me?
A7XBear A7XBear
18-21, M
Aug 2, 2010