Your agitation sounds very familiar to me. I associate it with my depression. Sometimes I will feel more agitation than the feeling of depression, but when i'm on my meds for depression, the aggitation is much better also.

I have PTSD and Major Psychotic Depression and I have to be on meds for the rest of my life. Irritability and agitation are the first signs that my depression is worsening, or my meds need changing. If I ignore that I end up with paranoid delusional thinking and next I get very suicidal. So I would suggest you go see pychiatrist or a psychologist and get a proper diagnosis and medication if needed.