After dinner sugar 349 and 204 in 15 min

Dear sir I am 37 years old. I have been checking my sugar level since one year. In December 2021 my Hb1ac  was 6.6 and FBS 107 and PBS  was 124 In February 2022 RBS was 93 on a particular day April 2022 Hba1c was  6.7 and 106 fast blood sugar 15 days back hba1c is 6.2 and fast 101. .. But yesterday my head was some dizzying and some irritation at forehead. Went to see doctor ,he has tested Sugar at finger blood. It was 174 just after food one hour. Evening I checked with other shop same finger blood after one hour , it was 349 shown and got scared checked after 15 minutes it was 204. Why my sugar level shown that much variation within 10 to 15 minutes. I am very fearing kindly guide me... whether finger tip blood sugar values correct or not