What to do if i have checked my blood sugar level after fasting 12 hours. its 7.7mmol/l. am i diabetic?

Yes: Hi a fasting serum glucose of 7.7 mM (which is 138.7 mg/dl) meets criteria for diabetes (fasting serum glucose 126 mg/dl or greater, or 7.0 mM or greater). If the value was on a finger stick meter, they're not approved for diagnosis, and I suggest redoing with a real serum glucose. Doesn't hurt to repeat to confirm abnormality in any event. Healthy diet & regular exercise help any drug work better