Major D happens to a lot of us. Often preceded by stressful life events, especially those we can't control.
In the same way an m.d. uses criteria for making a diagnosis, we can use this checklist of behavior and mood. There is comfort in knowing that we all do and feel about the same when our brain chemistry is out of kilter.
Major Depressive Episode Symptoms | Psych Central site has interactive quiz too.
I worked in social work and mental health for years and saw many magical turnarounds in people who felt like they were in the bottom of a black barrel and would never enjoy life again. My favorite turnaround was my own, following divorce.
Antidepressants are misunderstood as being feel good chemicals. Not so; their main thrust is to inhibit the brain from excessive reabsorption of serotonin, which is normally present in the tissues.