My MVA left me with a neck injury that is too dangerous to stabilize surgically, so I'm in a battle with a bevy of neuro symptoms. When I'm really struggling, my PT tells me to wear my cervical collar to keep my neck still.
You could give that a try and see if it didn't give you come relief from the headaches, etc... Never wear a collar for too long though, otherwise your muscles could atrophy and exasperate your symptoms.
Are you seeing anyone about your depression and anxiety? I don't mean just swallowing pills. A good psychologist could help you learn coping techniques. I suspect if you could improve your emotional wellbeing, you might feel a tad better physically, too. You should also consider contacting your local chapter of the Brain Injury Association. They can be a great source for information and support groups.
Quite a number of us are TBI moms, so we know it can be tough to get proper rest and downtime.