I have a headache in the lower left part of my head where my neck and skull connect and it will not go away what is wrong? Nothing I do is working and no matter what I try it always comes back in the exact same spot each time the pain is unbearable when I

Headache. From the location you are describing sounds like an occipital neuralgia from a pinched nerve. You might want to contact a neurologist or a pain management specialist for further evaluation and possible nerve block. Or the evaluation might be helpful for another source for the pain.
That. That is concerning and you need to be evaluated, and you may need imaging studies. Persistent head/neck pain is concerning for a variety of significant problems. If you develop vision changes, fever, or vomiting then you must be seen as an emergency, but please have this medically evaluated.