Hi, thank you for posting.
I have gone through your query and I understand your concerns.
The symptoms that you refer might be related to cerebral comotion(high intracarnial pressure).
Cerebral comotion caused by the hit is manifested with nausea and vomiting.
To confirm the diagnosis you need:
1. MRI of head.(Magnetic resonance imaging
2. Abdominal ultrasound
, to exclude a possible abdominal disease.
3. Complete blood count
4. Liver function test.
5. Urine test.
You should immediately consult your neurologist
I hope this information is helpful.