Reason for my depression : Life sucks and I knew it, from my childhood.
I feel better: When I am too busy to think about it. For now, work and family occupies my time mostly. I smile ( = cry ) when I see same depression pattern for my kid.
Imo, you should actively change your situation ( see a doc, have a hobby etc... more importantly, find positive in even small things )
Something like counting sheep - but in reverse.
I usually wander in external thoughts for .5 or 1 sec and come back to the last number. Then, sleep somewhere between 50-30