First of all, you need to be seen by a Psychiatrist, without which it is difficult to diagnose you. If the diagnosis turns out to be depression, there are various ways to handle it and medicines would form only a part of the treatment. The treatment also needs to be long term.

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.