I agree with JoMar

Likely subtle, non-imagable trauma in your lower C-spine and upper T-spine.

These are difficult to objectively diagnose so instead, you get therapy, chiropractic, osteopathic, or other gentle spine mobilization/

Also, possible compression trauma to the soft tissue between your skull and C-1.

A gentle traction and mobilization followed by VERY disciplined posture discipline, especially during sleep. Sleep on your back with almost no pillow lifting your head.

I had a similar vertical impact to my neck. I did great sleeping in a recliner chair so I could not roll to my side.

A therapist or chiro can try to mobilize the spine gently but you must be disciplined to always rest in a good, supported posture.