I took Seroquel when I first got diagnosed with PTSD. I hated it. It made me sleepy the entire day. The thing with me is, I also have ADHD, so my ADHD pill made me focus- it's supposed to help me with everyday stuff like school- but it made me focus on my stupid trauma.
Now I'm on something else. It starts with a C. Ciprolex or Cipralex or Ciprulex. (I can't read my psychiatrist's writing.) It's slow- won't take effect for a month, but it's better than nothing.
If you want to be all scientific about it, they block your neural pathways or something, so that the messages that "Something bad is going to happen" can't get to your brain. (I dropped Psychology 1000Y like halfway through the first semester.)
As for the flashbacks, focus on grounding. Eat something sour, like Sour Cherry Blasters (I love those things.) or chew some peppermint gum, or make index cards to take with you wherever you go to tell yourself "If you are in a fog this is why (insert the possible trigger in the "this is why space") For example, for me I've got "If you find yourself thinking of Steph, you've just walked into a bathroom. Nobody will hurt themselves here. People in university are planning OUT their lives, not planning to TAKE it." Write some facts too, like "There is NO POSSIBLE WAY this could happen now. This is what you can do if it happens again. (That's just some reassurance that you're older, and you're NOT going to freeze if your trauma really does happen again.)
Read the cards when you feel your anxiety level rising. Also, write some nice stuff on there too. Stuff like "I love you, You're strong etc. etc." I write jokes too, stuff like "Sorry you're feeling sick to your stomach." and "I know I'm being nice to you right now, I'm you." That kind of takes my mind off of it.
But yeah, I agree with the above poster as well. Therapy first, then drugs. In my opinion, drugs can actually limit how fast you process your trauma, or even ACCESS it. You've got to get to the root of the problem first.