I AM DIABETIC AND TAKING GLYCOMET GP1 HALF A TABLET

I AM DIABETIC AND TAKING GLYCOMET GP1 HALF A TABLET BEFORE DINNER SINCE LAST ONE YEAR BUT FROM THE LAST TWO MONTHS I HAVE BEEN SUFFERING FROM SEVERE HEADACHES AND SOMETIMES HEADACHE RESULTS IN VOMITTING AND LOW BLOODSUGAR AND WEAKNESS. WHEN I SKIP MY DOSE DUE TO LOW SUGAR IT BECOMES ALRIGHT WITH NO FEELING OF WEAKNESS BUT FURTHER IF I SKIP IT FOR THREE DAYS CONTINOUSLY THEN THERE IS NO WEAKNESS OR HEADACHE BUT SUGAR LEVEL INCREASESTO 200. KINDLY SUGGEST .