I do the same thing! Beating up on myself for stupid things/awkward moments I've said in the past is probably one of my favorite past times. It's like chain reaction, you think of one thing and it makes you think of EVERYTHING. I always get overwhelmed and freak out when that happens and sometimes wind up saying more stupid things to people lol.

I do this with other things too like my childhood.. I just rehash all the trauma I went through and get really angry at my family.