PSTD, Hypervigilance, & Triggers

I am SO sorry that you had the experience that you did.   I can't imagine how terrified you must have been.

From my own experiences, it sounds as if you're experiencing PSTD which triggers hypervigilance.  Blue Rose provided some great links, and I would strongly recommend considering engaging in counseling therapy and a support group for victims of violent crimes.

The word, "maybe," has no place, at this point.  You cannot go back into time and change your reaction to such a random, violent attack.  And, it doesn't matter how much time passes.   People can experience PSTD years after a trauma.  All it takes is some trigger to set off a chain reaction, and recognizing the triggers and learning management techniques can be a lifesaving and mind-saving endeavor.

Again, I'm so sorry that you had such a horrific experience.  Best wishes to you on your recovery.