Change of environment doesn't do much. Even when I travel I have my nightly flashbacks. For me the act of going to sleep is as much a trigger as my bedroom. I have done everything I could think of: meditation, herbal tea, exercise, no caffeine or sugar, distraction, truly convincing myself I wouldn't have a flashback--but they still come.
I have memories and I have flashbacks of my experiences, and the two are quite distinct. My flashbacks are much more vivid, they feel like they're happening over again, and I think I'm actually X years old again and I think the year is 199X/200X. During my memories, I am still aware that I am 19 and the year is 2009. In fact I can talk about my memories while remaining somewhat in the present (although I admit I do dissociate lightly when talking about my memories.) With my flashbacks, I'm in another place entirely.
It would be nice jillio if you just took my experience for what it was instead of trying to explain it within the frame of what you may have officially studied. I have had so many doctors deny me on the basis that they learned "this is impossible" or "that is impossible," but it obviously is since I am experiencing it. Many medical professionals get caught up in whether someone's case matches the textbook example, and take in the black and white statements made in many textbooks too heavily. There are always exceptions, there are patients whose cases stray from the classic one. So it would be nice if instead of telling me that what I feel is impossible, you can come to realize that maybe I know what I feel and that maybe my case is unusual.