You need to at least talk to a lawyer. Whether you'll be able to prove enough damages for them to actually take the case is another question, but tort lawyers will almost always consult with you without an up-front fee. It helps that you have neutral witnesses to your decompensation.

I hope you're also seeing a therapist. (If by MD you mean a psychiatrist, even if s/he does talk therapy, IME you'll get more attention from a psychologist or LiSW.) The best way to avoid PTSD is to deal with the emotional trauma soon after the incident. Of course it would help you document your emotional injuries too.