My mind races 24/7 with fear.

I start to imagine something bad happening, and then my mind doesn't stop. I see every single detail, gruesome images, imagining my new life after the terrible incident.
I mean horrifying stuff... It's like having constant nightmares. My biggest fears happen in my mind over and over.
I've gotten to the point where I have no control, and I drink alcohol to try to make it stop. Which I know doesn't help in the long run. My anxiety meds aren't even enough anymore.