amitriptyline

12 month ago, I got an headace, no regular pain releave drug can stop it, I have been taking amitriptyline for about 1 year, 10mg, I only take half of it every day before bed time for my headace. But I really want to stop taking it, however, every time I stopped taking it for 3 days, my headace would come back, and other affects such as fatigue, difficult to sleep, losing appetite, my blood preasure would rise up too.
shoud I stop taking it or keep having this medication forever?