No it is not very high.
If you have type1 diabetes then you need to test it everyday and if you have type 2 diabetes then you can test it once in two days.
Yes, specially if you have diabetes then foods rich in sugar can spike your blood glucose levels.
Yes, if you have fever you can take the medicine, however keep your doctor informed
Blood glucose test specifically the fasting sugar needs to be done with 8-12 hours fasting.