The reason its going down into your shoulder now is because the cause of the issue is stemming from the nerves in your neck which supply not only the muscles into your head, but also down into your shoulders and back. I agree with another post that it can be rather unsettling, although not dangerous, to have your neck "popped" by a chiropractor, but there are more than 250 different techniques to adjust a patient. Finding the technique that is right for you can take some time, just like finding the right MD, you may have to shop around.
The technique that I specialize in is not only specific, but extremely gentle; it's called Grostic. It's an upper cervical specific technique that is uniquely designed for you based on very detailed x-rays. I personally would never see a chiropractor that does not take films, as it's like having surgery without knowing what's going on inside. Films not only rule out other conditions that may be contraindicated to getting an adjustment, but also determines how to properly adjust the patient for them to receive the most benefit.
I'm in Plano, so it would be a haul for you. But, there is another upper cervical doc right in Denton. I would recommend DeHart Chiropractic Clinic on Elm Street,###-###-#### . Also, go to www.upcspine.com, which is a patient-run website to get further information on the technique.
It would be worth it to just get it checked out and see if it would be an alternative to a lifetime of medication--which would be the only route in the medical world. God Bless.