I have pain on the right side of my head, feel watery behind my eyes, nasal congested, slight nausea. sinus headache or something else?

Yes and yes: Nausea + head pain can occur with sinusitis &/or migraines. Sinusitis and migraines are closely related--One can cause the other, and you can eventually have both. If no fever,treat the sinusitis first with a neti pot and/or long acting pseudoephedrine (if you don't have high BP), use naproxen if you still have a headache. If symptoms don't improve in a few days, go to your clinic to follow up