Hi Sophie,
See your GP and tell him ALL your symptoms - write them down - then ask to be referred to your local Headache Clinic. They are usually run by Neurologists (something they are good at) and their staff and it is a perfectly reasonable request on your part. As you can tell I am in England - Yorkshire.
If your GP won't agree to this perfectly valid request after 10 years then register with a new one.
If you don't want to change you can complain to your Practice Manager in the first instance - that will be the Senior Doctor. Failing that you can complain to the NHS directly. Here, there is no excuse for shoddy GP services - that's left to Neuros and overworked Hospital Depts.

Dave.