I think you need to find a Physiatrist (Physical Medicine and Rehabilitation) or physical therapist skilled in whiplash to assess you. You may just have a subtle upper neck injury. It can cause all of the symptoms you are experiencing. Physiatrists are often affiliated with Neuro Rehab hospitals and clinics. Upper cervical chiropractors can also help.

In the mean time, you need to take care of your neck with good head and neck posture discipline when you are sleeping and resting. Inflammation in the upper neck can disrupt blood flow to the brain and cause the symptoms you are experiencing. Icing it would be worthwhile.

You do not have a TBI. Even most moderate to severe concussions are just categorized as mTBIs, mild traumatic brain injuries.

What was your previous 'serious TBI' ?

I bet you saw the movie Concussion. It and other media presentations on concussions have scared plenty of people such that they are afraid of even minor head bumps or jarring.

Check out the Vitamins sticky at the top. It has some good information.