I am really sorry to hear what you are going through. If you are still having severe headaches and nausea, then please go back to the ER. You may need a CT scan/MRI of head and neck along with a complete examination f the ear on the affected side. Often injuries of brain, spinal cord and vertebral column and ear injuries are missed on the first scan.
Other than this, you need to consult a neurologist and get the seizures investigated. You will need to take medications for this. Please avoid living alone, and carpet your floors to avoid injuries, and please do not drive. Please consult a neurologist immediately. Take care!