I think the best advice I ever got to stop myself from getting in my head over issues i was having with a partner/friend was “Are you deciding on ultimatums in your relationship without the other persons knowledge or consent? Are you having conversations in your head where the other party is a projection you supply the responses for? If so; you have done this person a huge disservice in not allowing them to answer on their own terms. You have done so much architecture around this problem in your mind that is impenetrable for anyone who was not there when it was being built.”
That shit really changed my life and honestly? I think made me a nicer person to be around.