I used to pass out when my senses were overloaded. Which was always for about 7 years. I don't think you need to have autism to have this type of behaviour. My therapist shook her head when I used to think I was autistic. No, she said, you are traumatized. It makes sense because the nervous system baseline is jacked up. I think the name of the game is to reduce stress as much as is humanly possible in order to give your nervous system a break. That means building a plan to manage stressors better. You may find that your hypervigilence naturally eases.