You aren't alone. Try not to be so frightened. Many people suffer from trauma and have PTSD. You aren't alone.

Although I am not a dr, it does sound to me like PTSD. Last year I had a somewhat similar occurrence when my PTSD really got triggered. I called my therapist panicked. She specializes in PTSD, particularly sexual trauma. As we talked through the feelings of an event of what to me resurfacing was unrelated to my trauma. I felt nauseous because I realized it was a bit more related than I thought. The common factor was me. My therapist J said to take the focus off the terror and self loathing of the past and focus on the present. I needed to ask what positive can I do now? How can I take care of me right now?

I made a list of a couple realistic healthy obtainable short term goals. I would go to my small prayer group that night as they offered solace. I would journal about my feelings. I would go to my next therapy appt.
sometimes the best way for me to fight the terror is one foot in front of the other and focus only on those steps.

If you don't have a therapist, I would definitely advise getting one. If you can, one who specializes in PTSD. It really sounds like you are going to need help in this process moving through PTSD.

Try to keep breathing. Try to keep moving. Be gentle on yourself. You will make it. You are not alone.