Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to review your medical history and examine you personally, it is difficult for me to give you a diagnosis. Whether or not a headache is concerning depends on whether or not you usually get headaches (a very painful headache that lasts for more than a few hours in a person who usually does not experience headaches is usually concerning. If someone often experiences headaches, and their headache is not too different from their usual headaches, it is likely the headache is not concerning etc. However, taking a history and doing a physical examination are very important in assessing a patient with headaches).
There are a number of possible causes that come to mind given the description you have provided above, a popping sensation in your neck followed by neck pain and headache and face and eye discomfort.
Causes of neck pain associated with headache are cervicogenic headache and occipital neuralgia.
Cervicogenic headache is a headache that is "referred" to the head from bony structures, muscles, and other soft tissue in the neck and shoulders. Symptoms are usually one-sided and include: precipitation of head pain by neck movement or awkward neck positions, head pain when external pressure is applied to the neck or occipital region, restricted range of motion of the neck, and neck, shoulder and arm pain. Treatment for cervicogenic headache includes physical therapy, medications, behavioral therapy, and other modalities.
Occipital neuralgia is caused by irritation or injury to two nerves that run from the upper neck to the back of the head. The irritation could be due to neck trauma, pinching of the nerves (by muscles or arthritis), and other causes. Symptoms include a piercing sharp pain that travels from the upper neck to the back of the head and behind the ears. It is usually a one sided pain but can be on both sides of the head. Treatment includes physical therapy, medications, and in some cases injections, "nerve blocks", during which a physician injects the irritated nerves with an anesthetic.
A concerning cause of neck pain associated with headache is a dissection: a small tear in the blood vessels that travel up the neck to the brain. This can occur spontaneously in people with certain conditions that affect the blood vessels, after neck trauma, or after chiropractic manipulation of the neck. The pain is often but not always associated with some sort of neurologic deficit as a dissection can often lead to a stroke.
I suggest that if your neck pain/ headache persists and/or becomes more severe, and/or if you develop neurologic signs like weakness on one side of the body, slurring of speech, double vision, difficulty speaking, and so on that you be seen immediately by a doctor. If you frequently experience headaches or neck pain and are not finding relief, evaluation by a neurologist, and perhaps a headache specialist, might be helpful for you.
