is the likely cause...
Based on your description it looks like right eye conjunctivitis
- infection of the outer layer of sclera (white part). Associated sinus congestion and headache are part of the same infection. I would start you with tylenol
pain and flu to control pain, redness
and sinus congestion. In addition I suggest you to try steam inhalation.
Besides the above over the counter measures, I would also prescribe mupirocin
eye ointment since the eye is very red and inflammed. Your local doctor will know about this drug.
Though it looks severe now, I would not be very worried as long as your vision is clear. Try the tylenol pain and flu and steam inhalation and consider visiting your local doctor for topical eye applicants.