hi,, i have understood your problems and concerns.. headache, sad mood, fear about future accidents, post traumatic stress problems, sleep disturbances, flashbacks of accidents are very common after accidental head injury.. the anxiety symptoms and panic attacks u are experiencing are mostly because of the fear and stress u have witnessed during your past accidents.. in my opinion u shud consult a psychotherapist or counselor and tell him about your issues related to past head injuries..when u talk about your experiences repeatedly your anxiety will decrease on its own.. apart from this i am here suggesting the drugs that u shud take for at least 6 months.. drugs are: tablet. sertraline [zoloft 50 mg] at night.. increase the dose to 100 mg after 15 days..u can go up to 200 mg in a day, depending upon the beneficial effects.. tablet. clonazepam [klonopin 0.25 mg] twice daily to reduce your anxiety level..u shud gradually reduce the dose to once a day and finally stop clonazepam within next 2 months.. if u have sleep disturbance then u can take tablet. zolpidem [ambien 10 mg] at bed time..it is optional.. with the help of medication u ll be able to control your anxiety and the counseling will help u to remove from the grass root level.. i hope u ll find this advice helpful.. best luck..