That’s how I feel - it can be a bottomless well, and tough to climb out of, once you’re a few buy-ins down.
I usually set a stop-loss in cash games (2-3 BI) for two reasons. The first, as stated, is that once you're in a deep hole, it becomes more and more difficult to climb out. The second is that I often find myself playing non-optimally when stuck a lot, so a stop-loss helps me avoid putting myself in that position.