Welcome to healthcare magic!
A head bang on the ground can lead to any amount of head injury
to Catastrophic brain insult due to massive intracranial bleeds.
I think you did not have any loss of consciousness
, seizure, vomiting
or ear bleed which are the cardinal signs of serious brain injuries.
You had a dizziness
which suggests a concussion at best.
A concussion is fully reversed within hours to days at maximum.
So probably you have developed a phobia of the event.
Still to be on safer side get a non contrast CT Brain and review to your physician or send the image to me in the follow up query
I hope this advise would be helpful for you.
Still if you have any queries or doubts, please write me back,
I would be happy to solve them.
Wish you a great health!