i used to fuck that one up two.
i find that using the word 'context' is helpful.
as in, "hey this is the context of why i thought/acted that way. it does not excuse my hurting you in any way. it's only context. clearly i misunderstood something and thus i screwed up badly. i offer you this context only because i really don't want to make this same error again, and thus risk further injury. i'm so sorry this happened and i want to be responsible for my actions. you don't have to answer me right now, but if you can think of anything else i might be mistaken about in terms of this situation, i'd really appreciate further clarification."