A car accident is a trauma that could cause PTSD. Your description sounds somewhat like what I feel as a dissociative symptom. (I feel like the top of my head is floating off, or that the whole room has a hollow sound, I get burning, I have had difficulty swallowing, and the feeling that there is something in my throat.
I have a herniated disc in my neck. I have PTSD. With the PTSD, I tend to get physically tight. My shoulders, neck, arms and back will sometimes actually spasm. That tightness aggravates my neck.
Neck injuries from an accident can show up some time afterward, especially if they are overlooked in the ER.
If they imaged your neck after the accident, you may be able to get a comparative image, to see if there was something slight, that was disregarded, on the first image.
My insurance covers Chirpractor visits that include heat, massage, and adjustment. I have gotten significant relief that physical therapy did not help. And I like the massage. LOL
I would seek help with a therapist to discuss if the accident is an issue, or if there might be something else in your past that you have disregarded as a possible issue. Kids frequently are unaware. I have a very distant image of the neighbor 6 yo boy who was killed riding his bike on the wrong side of a tight narrow road, when he met an oncoming truck.
It is a horrible image for an adult to think. I just recently came to seeing the horror of it as an adult. Before I was just numb about it, because the enormity of it was beyond my 9yo scope.
Following the wreck did you have any sort of treatment? Mental treatment? As in talk theraphy and the likes? Most people are happy if they walk away from wrecks. They can just get on with their lives. Years later the effects of the shock can hit them. It is still there. Lingering on. All it may take is a trigger to set it off. Be it that you see a car crash, or hear skidding noises. It could all just come flooding back. I ended up under a car at about 16. It didn't effect me till I was I just 21 and a mate died in a car wreck. One triggered off the other. Were i am not saying that is the answer. I am saying it can't be ruled out. It might be something worth looking into. And for what it is worth I sleep like a horse. I am almost standing. Can't lay out flat. No matter what. It is just impossible for me. I would feel a lot worse. I use a sofa bed. In the sofa position. So you are not alone there. Anxiety can bring on many things. Strange little things. That can differ from person to person. We all have our own little odd ways of getting by. Call them rituals if you want. They come over time. Whatever it takes. If it helps we will adapt to it.
i am a visitor to this site , I have a couple of thoughts for you , have you considered you may have low Blood sugar, (Hypoglecemia ) not diabetes , rhe symptoms you describe are like that especially if a sweet drink helps, Have you noticed that it happens when you havent eaten much if anything, then when you eat some high carb you feel better. Anxiety can also cause physical symptoms. Next time you feel like this make ss ome notes , try drinking that Juice see if you do feel better. Good Luck not much fun is it ,I have been there.