Diabetes problem. Keep kindly reply me.

Hi, I have undergone a whole medical body checkup on September 2019 my sugar level before fasting is 102mg/dl And after food 152mg/dl But in A1c test is normal I don't have pre-diabetes anything. But testing took long time since I go for early morning 8 clock but I'm very hungry they took the fasting test after 9 only. So I go for another lab to check my sugar level which is in October 2019 sugar level is fasting 79 mg/dl After food is 124mg/dl which is normal Now I need a clarification for diabetes since I'm Feeling some tingling and some pain in my nervous symptoms of diabetes I'm worried can anyone tell me whether a pre-diabetes or any diabetes can occur so fast to a person with in six months of testing sugar level. And one more clarification how long it will take for diabetes please keep kindly reply me. Thanks in advance,