I am a neurologistn and i thank you for posting your question in thuis web site
i assure you that (based upon the symptoms posted) you may not have major brain injury
due to this. Injury of the scalp
can be very painful as in your case. How ever, you have to understand that barin injury some times may produce overt clinical symptoms and a clinical examination may be normal. I sincerely advise you to undergo a CT scan
of brain to rule out a brain injury. If this is ruled out, you will need simple analgesics for few days.
Further, i advise you not to take a chance and get examined by a local neurophysician who can help you in a better way
Hope this clarifies