Flashbacks are awful.
If they happen when you're in public, you're basically screwed.
For me, when one happens I just freeze and stare at a fixed spot on the wall or the floor and the terror plays over and over in my head. It's weird, I've noticed that the little movie of the trauma in my brain is quite creatively filmed! Sometimes it's like a time-lapse footage film. Sometimes the colors and surroundings are all distorted in an ominous, impending doom sort of way. Sometimes it's hyper vivid (I hate those times) and sometimes details I haven't even processed yet arise.
When flashbacks happen to me, I can't talk or understand what people are saying. Sometimes I cry, but usually I just get really stiff and stare. If I am in public, I try hard when I feel one coming to find a place where I can be alone. I don't know if flashbacks can be stopped before they happen, or if maybe I am just not in the phase of my "recovery" from the event where I can stop them...
My big triggers:
-any situation where my movement is being restricted-- whether it be being in a car or being socially expected to stay still like when I go to church and have to sit still through the service. This is triggering because it reminds me of: handcuffs, shackles, detainment, holding cell, jail cell, total loss of control.
-the following words and images: police, D.A., hearing, charges, allegations, arrest, reasonable doubt, field, rope, my own name, homeless, camping, tents, woods... etc.
I've found that making a trigger chart that is very thorough is helpful. List the trigger, how it makes you feel, and what specific part of the trauma the trigger arose from. It's hard to face this stuff head on. I whole heartedly agree with 50msns sentiments about smoking weed being helpful. Out of all the psych meds I've been put on for this acute PTSD, its the ganj that really helps me temporarily work through the memories with less of an emotional response. It's so hard to work through this stuff when you're constantly stopped by panic attacks or shutting down into depersonalization!
To everyone suffering from PTSD... I know you feel alone-- and in one sense you are. We have to deal with our stuff ourselves. No one can come into our brains and pick up all the pieces and glue everything back together to the way it was before. BUT-- in another sense, you are SO not alone. Reach out if and when you can. Don't allow it to suck you into isolation and despair. Learn about PTSD, but don't make PTSD define you. You are so much more than this. You may feel like you've lost parts of yourself... but have hope. Things come back, often very suddenly and unexpectedly, in PTSD. Keep on going-- if for nothing else, for the possibility of the joy of re-finding yourself. It's going to be worth it in the end.