Front/top head pressure, tense eyes, unbalanced feeling, weakness, small headache, neck soreness, problem concentrating, fatigue. sinus problems?

May be not: At your age it sounds more like anxiety disorder or depression rather than sinus headache.

Headaches: Headaches, unbalanced feeling, neck soreness , top head soreness are symptoms of concern and needs further investigations to evaluate for vascular, intracranial , meningeal problems from various different causes in addition to sinuses , inner ear problems etc . Consult with your doctor.