Dear
Welcome to HCM
We understand your concerns
I went through your details. You should understand the difference between disappointment and
depression. Disappointment, frustration, disgust etc are emotional problems which can provide symptoms just like those of depression. The silver lining is, these symptoms will be of short duration compared to long lasting and chronic symptoms of depression.
In your case, your girl friend of one and a half year left you for another. You are deeply hurt, disappointed, disgusted and therefore emotional. Anger, aggression,
stress,
lethargy,
lack of appetite, lack of thirst, lack of sleep, being lonely, obsession etc are part of this. You will feel and experience these symptoms for some days if you don;t keep yourself engaged. Then, slowly, these symptoms should vanish.
If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute detail possible.
Hope this answers your query. Further clarifications are welcome.
Good luck. Take care.