Got concusion 10\18 from fall, still experiencing headaches -doc put me on amitriptyline - how much longer will they last?

HA after concussion: The symptoms associated with postconcussion syndrome (e.g., headaches) are greatest within the first 7 to 10 days for most patients. At one month, symptoms are improved and often resolved. The vast majority of patients have largely recovered by three months. A minority (10 to 15%) have symptoms lasting one year or longer. Unfortunately, it is not possible to know how much longer they will last.