You might just have West Nile which is very very common in Canada..see a doctor as soon as possible!
NO! Maybe if you were centeral america... MAYBE!!! You did not get Malaria in New York! It could be lyme disease... Go to the doctor!
I would see the doctor. You could have picked up a flu bug while gone and it is just now making you sick, it takes about 9 days for the bug to really take hold.
Contracting Malaria in North America? NOT POSSIBLE at ALL.
Possible something you ate that didn't agree with you in NY or some activity you did in NY? Maybe an exposure to someone who was sick (in NY, on the plane, etc.)?
As everyone else has stated, go to the doctor.