Hello! Head injury can be serious even when it is a closed one. Closed head injury are considered all head injuries where the dura (the outer layer of the brain) is intact, even if the skull is fractured or cracked. Headache is the mos common complain after head injury. In your case i would suggest to see a doctor, since the symptoms as you mentioned in your question, are worsening. Headache and them vomiting may be a sign of concussion (the mildest form of traumatic brain injury), or even increased intracranial pressure which may be caused by intracranial hemorrhage. The prognosis is worse if neurologic signs (like amnesia, confusion, nausea, vomiting, agitation, somnolence, vertigo, seizures) are present from the beginning, but they may show later on. You have to see a doctor and if the symtomps persist or worsen a CT scan has to be performed to exclude intracranial bleeding. I hope i have been of help.