Having a sad feeling continuously.

I am having a continuous sad feeling i am not able to feel happy at alI. I am not able to sleep at night at day time I feel sleepy. I am not enjoying my work don't want to well dress up for office taking too much leaves without reason and sit back at home. I do not want to see too much people around me. Avoiding my friends as well haven't went to meet them from a long time approx 3-4 months everytime I make an excuse I do  not know why but I do not want to meet. From sometime I  have started running after office I do run for at least 1 hour that's the only time I feel a little okay. I have also started writing poems. Sometimes feels like I m worthless that I haven't done anything to my parents to my siblings. I do have lots of stupid thoughts in my mind related to my future or any rendom stupid thought. It's all very difficult to make someone understand. Sometimes I just want to sit on floor and cry a lot without any reason. I just want to stop this sadness...