I was in a similar event to the one that occurred today and I wish I would’ve gotten help sooner, but I didn’t accept that I had ptsd for a long time. 7 years after what happened I got help, and I wish I would’ve addressed it sooner, I lived paranoid for many years and would have panic attacks at the slightest thing, like the noise a textbook makes when it’s dropped. Please consider getting help or at least just talking to a counselor even once, it can really really help you. You can feel normal and safe again.