Thank you for the information,
The pain and tenderness in the cheek bone can be due to infection or inflammation of sinus or sinusitis.
This can be due to infection of the upper molar teeth.
When you had nasal congestion, sinusitis is a possibility here.
The lightheadedness can be due to sinus infection.
The symptoms might have started as viral infection which usually resolve by itself with supportive therapy.
Viral infection usually gets better in 3-5 days.
Sometimes, bacterial super infection can occur during post viral period.
In that case, start of antibiotic reduces the symptoms.
Keep adequate hydration by plenty of fluid & electrolyte solutions, light tea, soup.
Anticold tablet like advil cold can help to reduce the pain.
When the symptoms are present for 2 weeks, bacterial infection can be possible.
Sinus scan can be required.
You should get it checked by doctor to start treatment asap.
I hope this information helps.
I will be happy to assist, if you need any clarification.
Please feel free for any follow up query.