I never try to work things out when I'm really up or really down.... I just can't think straight....
I find it easier to work things out after they have happened, like I was having a conversation, someone said something, I got upset. Later when I'm not so upset I think what was it about what the person said that upset me, what did I let it say about me.....
take it one thought at a time, recognise the thought, work out the pattern, then it gets quicker and easier....