This is a problem that you need to get seen for very soon. Vertigo is treated by many different types of physicians (
primary care physicians, ear nose and
throat doctors, and neurologists). Since you have a history of a head injury, I think it is best if you see a
neurologist for these symptoms.
In most people, vertigo is caused by a benign problem in the inner ear where vertigo is induced by certain movements. In your case, I am worried that your vertigo is due to some neurological problem that came about from the accident. If this is the case, then you need to be followed by a brain specialties (neurologist). They will know what type of medicines are best for someone in your situation.
I suggest that you schedule an appointment with a neurologist as soon as possible. You will need to bring with you any records including imaging from your accident. He or she can take a detailed history of your vertigo attacks including how they come about, and perform a thorough neurological exam. The neurologist may want to get more detailed head imaging such as an MRI. Hopefully, you will get to the bottom of what is causing your vertigo and come up with a treatment plan on how to fight it. Good luck.