Some fights are worth having. Most are worth sleeping on first.

A few disagreements genuinely need to happen, and dodging those only stores up the cost. The trouble is that urgency is a terrible guide to which is which, since almost everything feels urgent while you are angry. Sleep sorts them with surprising reliability.

Set a rule for yourself: nothing important gets said tonight unless somebody is in danger. Write the message and leave it unsent. By morning you will either have lost interest, which answers the question, or you will still want the conversation and will have a far better version of it.