As you have suspected, most probably you have caught infection from your GM.
With the information given by you, all of your symptoms can be explained by your upper respiratory infection
except blurring of vision that is most probably not due to this infection.
If you did not suffer from sinus
problem in recent past you may do following things:
Take plenty of warm fluids, nutritious food, avoid mental and physical stress
as much as possible.
Do steam inhalation.
You can take a pain killer tablet for headache etc.
But if your symptoms are progressing you may need to see a GP/ENT specialist
If you had past sinus problem better see an ENT specialist.
If your blurring of vision persists you may need to see an eye specialist.
Wish you good health.