Thank you for asking. I can understand the distress you are through. Your complaints are well suggestiive of a depression like condition. You need to understand it may happen to anyone, and at times, there may not be any obvious stressor known. Although, external stress in an important factor, however certain hormonal changes esp. in females does predispose for depression. You must consider visiting a psychiatrist as he can conduct a detailed interview and establish a diagnosis. In case it is a depression, with suitable medication and treatment it can be cured.