I've had a lot of bad emotional flashbacks, very much as you describe, sometimes quite different. For me, it is much more like having the emotional stress of childhood; fear, panic, isolation, but in the context of what's happening around me. Mine have most generally in the context of maternal transference with my T. Emotional flashbacks are particularly troubling because they don't have a specific point of reference, or sometimes it's hazy.

I haven't done DBT. EMDR helped some. Mostly, it's been trial-and-error with my T to figure out how to get myself out of the flashback. Usually, it's as simple as the two of us just talking. Most importantly has been to identify signs or cues that I'm in one of these flashbacks.

This is a good piece that might help understanding: https://www.psychotherapy.net/article/complex-ptsd