Where should a stop-loss go?
Not at some support level, but at the point where your own reasoning would stop holding up.
The same applies to life and business.
PS: The scariest thing is never having thought about what your reasoning actually is, or knowing under what conditions it would fail.
Size your position based on the loss you can bear. Use position management to control drawdown risk.
First determine the maximum loss you can bear on this trade, then work backward to how large a position you should open, rather than first choosing a position size by feel and then passively bearing the loss.