I have Cervicogenic Headaches. They start at the top of my neck and go up either or both sides of the back of my head. If they go untreated they turn into migraines. Some of you sound like you might have similar problems. (I did get double whiplash 10 years ago in a car accident but from what I read there are various causes.) I had a headache pretty much all the time for a couple years. They didn’t start until over 3 years after my accident. Just information and something else to search on.
Has your doctor mentioned occipital neuralgia? This is a disorder of the second and third cranial nerves (which combine and form the occipital nerves). Some think pain is due to muscle contraction on the nerves, but there is also the theory that there is pressure on the C2 nerve root (like a herniated disc in a way) and that releasing the pressure helps relieve the pain. It is worth mentioning to your doctor as another possibility in the differential diagnosis. I am a physician and when you mentioned your symptoms were always occiptal but poorly responsive to triptans it made me wonder about occipital neuralgia. Hope you feel better soon!