What could be causing this headache that is hurting the back of my head and upper neck with plugged ears as well?

Is it a cold?: Sounds like you may have a cold or allergies how long has headache been bothering you? Any other symptoms? (nausea, vomiting, visual changes, pain down back/legs, cough, stuffy/runny nose, itchy eyes or throat, fever, head pain when you lay down or try to sleep?) often a cold can do what you describe drink warm beverages, consider Ibuprofen if it's safe for you to use. See doc if worse.