I got a bad blow to the head a little
Best to go to the ER, should not have waited for insurance approval.
Welcome to Ask a Doctor service.
It is highly unlikely for head injury to cause trouble now after 1 month, ideally head injuries should be investigated immediately in an emergency setting.
Since you do seem to have something going on with your neck, mostly a pinched nerve in the upper cervical region, you must go to the ER and get yourself evaluated completely.
And if CT scan is indeed required, ER doctors would usually get it done.
I hope that answers your query.