Hello and hope you are doing well.
Sinus infections can cause dizziness, as inflammation in the nose and sinuses can cause inflammation around the Eustachian tube, which is the tube that runs from the back of the nose to the middle ear and is responsible for draining the middle ear of fluid. If there is Eustachian tube dysfunction from nose or sinus inflammation, fluid can remain in the middle ear which can lead to dizziness. You will need to consult your primary care physician for proper assessment. In the meantime practice good breathing exercises, humidify your room and do steam inhalations.
Hope this helped and do keep us posted.
It could be a sinus infection or an ear infection.
You should really see a doctor, especially when vertigo is involved.
If you can't see a doctor at this time then you could try the following:
Sinus rinse ( neti pot )
Antihistamines ( as it could be allergies and not a cold )
Claritin nasal spray
However, I feel that it would be beneficial for you to see a doctor, as you are describing symptoms of silent pneumonia as well.