Your standard should survive the mood that tries to renegotiate it.

Moods are persuasive and temporary, and they specialise in renegotiating agreements made by a steadier version of you. The negotiation always feels reasonable in the moment, which is precisely the problem, because you are being asked to revise a decision by the party least qualified to revise it. A standard that only holds when you feel fine is not a standard. It is a preference with good weather.

Set the terms in advance and put them somewhere you will see them when you are wavering. Then treat a bad mood as information about your state rather than instruction about your commitments. You can feel terrible and still keep the agreement.