Depression is just the pits

I am through the worst now but depression is just the pits. One moment you are in sunshine and next you feel like all the happiness has been sucked out of your life. My friends say it is because I take on everyone else's problems but they don't understand that it is because I choose to. Why should I ignore another persons pain when just a few words of comfort can lighten their load. I think we will never agree on what I believe.