Depression and psychological anxiety.

I am working in a banking sector in IT department. I am interacting with my team mate as well with other staff also. Now a days I am in depression. Actually one girl is in my team and she possess the same characters as I am searching in my better half and the same characters being possessed by one more girl. With both of them I am interacting daily. I am more serious about the girl who is not in my team but if some one get in touch with the girl who is in my team I feel anxious and this makes me think about her also. I am not able to concentrate on my further studies as well as in work. No movies is able to make me happy or divert my mind from them. I want to cry. I love loneliness and sad song heals me. Please help me to get out of the situations.