How should I manage acne that appears at the hairline between my face and hair?

hello?
I get acne when I'm stressed.
It always grows at the boundary between the face and hair.
It sometimes grows on my hair too, which is frustrating.
How should I manage acne like this?
I can't wash my hair with foam cleanser when washing my face, either...
That doesn't mean I don't wash my hair, though.