Hello Friend, Good that you are seeking a help. All your symptoms are sign of  depression. You may be over thinking about one particular issues and about past or future. These thought can trigger stress at  both body and mental level and you are experiencing few of them now. Better to take a professional counselling support to assess yourself first, so that you understand your problem better and also be able to figure out the root cause and suitable solutions to overcome.

Feeling low, having crying spells, sleep and appetite disturbances, and difficulty in concentration and attention are some of the signs of Depression. Consult a Psychiatrist for a detailed assessment. It is likely with medication and counseling the symptoms will improve. If you are feeling suicidal or hopeless consult a Psychiatrist immediately.