Just talk to them about it.

Let them know that you’re not in a place where you have the headspace for this, and be specific about what’s draining for you. Try to be thoughtful in how you phrase it, make a lot of “I feel x way when you do this action” sort of statements. It helps keep blame off of them in the dialogue (which is helpful because it can reduce defensiveness) because you’re not telling them “you make me feel this” and is instead you telling them that their action is having an effect they didn’t intend.

if they give a fuck, they’ll try to be mindful of it.

If they don’t, and aren’t, then you 100% have a good reason for just being extremely business-like with them.