What Causes Persistent Headache And Pain At Back Of Neck?

Hi Doctor. I have been getting headaches for the past month or so and have been in and out of A&E also. Apparently have either anxiety or panic disorder but personally don't feel that I do. These headaches aren't something that just comes and goess, I was perscribed xanax and zolpidem. I was also told that it could just be tension headaches as I get pain at the back of my neck sometimes. I bought a BP monitor today and it just tested 168/118 an HR of 110. Im a 20yr old diabetic and it just bothers me not knowing exactly whats wrong. I might be going of an mri or CT scan in the coming weeks if the constant headaches keep up and was just curious to see if you or anyone else had advise for me - even tips on how I could possibly reduce these aches? thanks