This happens to me and it drives me crazy. I can be doing just fine and all of a sudden I'm crying uncontrollably, not able to catch or stop myself. Like @Solara I think mine are more emotional flashbacks complete with feelings of shame, hopelessness and fear. Sometimes I can ground myself using nice hand cream to self soothe, drinking herbal tea or going for a walk outside. At other times I just need to ride it out and know that it'll stop at some point. It's horrible though, I hate being so obviously upset.