Joe,
I am so sorry that you had so much trouble with the medications. I have suffered from bad headaches and migraines since my concussion. I also am very sensitive to medications.
For nausea what helps me the most is chewing on a piece of ginger or drinking ginger tea.
For the headaches I would recommend that you read 15 Natural Remedies for Migraine Headaches by Jay S. Cohen.
Also, your doctor should give you something to take in case you do get a bad headache.
Acupuncture has helped me a lot, but you need to find a skilled acupuncturist who knows how to work with concussions or brain injuries.
I hope that you will find the help that you need.
ShellyK