What to do if i'm feeling very thirsty and i have checked my fasting blood sugar level which is 98 mg/dl , is it normal?

Probably: Thirst will come with a high sugar because it makes the body sense a high osmolarity and triggers a thirst. High sodium intake can do the dame so your glucose could be normal but if you had high salt food ( take out Chinese for eg) you may have a thirst due to the MSG

Sugar and thrist: You glucose level of 98 mg/dl is normal. Diabetes who have high glucose readings, which causes an osmotic diuresis, that makes them urinate a large amount of urine. That is what makes them thirsty. If you are not urinating excessively, you should not have an elevated glucose. Perhaps you need a greater intake of fluids.