I could be having a great day and enjoying it until a friend would do something like a light slap on the face and it just knocks out of my mood and into this horrible episode that sometimes takes forever to go away, I wasn't abused or anything like that apart from the odd slap when I was a younger child, I don't know what to call it but I'm feeling it more and more, I don't really have a reason to feel this way, if anything I should be happy but I just don't feel happy. Could anyone help me understand what exactly this is?