What are some things that can make you dizzy and forgetful PLEASE HELP?

I have been dizzy for a while and my doctor treated me for my sinus infection and said if we fix this your dizziness it hasnt gone away and i have been on the antibiotics for 3 days they said three days is usually the turn around however lately i have been extra forgetful so i was wondering if the dizziness from the sinus infection can cause that or some othere possible reasons for this