If I could simplify depression in one word, it would be 'guilt'. I'm so sorry that you are suffering, I know exactly how horrible it is to feel the blues. But I promise you that tomorrow will be a better day, and even a disgusting feeling as guilt could vanish when you realize that we are just humans with flaws; as soon as we are making up or trying to correct our 'mistakes', we have to let go and move on! We, people who live with depression, we tend to feel hopeless and really disappointed at ourselves, which is completely fine but it has to end at some point. It's really hard to see a light at the end of the tunnel, but hold on to the tiny little piece of hope that you have inside you, be perseverant...
You are important, and you will overcome this pain.