Depression. What should i do?

I feel like my depression has increased and nearly reaching to its extreme point. I am always blank in mind and life or too much going on my mind that I don't know what's going. Not able to recollect my days happenings. Feel heavy in heart and want to cry. Feel hopeless. Feel that I am good for nothing and cannot do anything. Not worth anything. Can not concentrate on anything even my studies as I am a student. Don't feel good, excited or enjoy things which I used to love and enjoy and even spend lot of my time. I feel I and wasting my life. Just living but don't know what's going on or what I am learning but I am just alive not living life I feel. I get anxiety problem sometimes because of it. I tried my best but how ever I do and what ever I do to come out of it and even come out a little. But always fall very badly and deep. What should I do? How to recover I don't want to go out totally from my sense and don't know anything which some how I am! Need help!