Gradual erosion.

That is, in the years after my first persistent depression symptoms, when depression wasn't diagnosed, I drew on my own personal reserves of resilience, conscious attempts to improve my sleep hygiene, and diet and exercise to keep myself going.

It became harder and harder to do less and less.

Eventually depression, etc. eroded me such that I withdrew / was withdrawn / was kicked out of "normal" life.

Some **** still falls on me, but less than before.