Something like counting sheep - but in reverse.

1. Count down from 100 to 0
2. Imagine each number ( like you are viewing in a calculator display or in any font you like )
3. External thoughts may come and go , consistently come back to the last number you have seen.

I usually wander in external thoughts for .5 or 1 sec and come back to the last number. Then, sleep somewhere between 50-30

4. For morning time / loud surroundings, use a White noise music. Low volume on a Noise cancellation earphone.

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 )