Chronic Migraine and Personality Changes

Whats wrong with me? I started having chronic migraine and it's been nearly 2 years now. I tried some medications: different brands of birth control on and off then this started. Amitriptyline 10mg once, diazepam 2mg once, pregabalin 25mg once, zolpidem 10mg 5 times, diphenhydramate 50mg 5 times. My personality has changed, I'm always irritable, can't think, can't feel. I don't know what happened to me and if the medicines damaged my brain. My head still hurts everyday on the left burning and I can't think or feel. I can try nortriptyline but I am unsure to try it. Is it dangerous?