What are you *feeling* in these situations where you end up in tears?

I think my tears are sometimes PTSD-related, because I cry when I feel pinned in, pushed, cornered--and that can happen with a nuance in a person's tone or the way people stand around me. At these times the tears are clearly inappropriate. However, crying when you're sad, frustrated, or very angry is more typical, and of course with PTSD these emotions are more at the forefront.