My random blood sugar result came 12.2g/dl is it too high am i suffering from gestational diabetes? how can i control it?

Get units right: Blood glucose is measured in mg/Dl, with a 'normal' fasting range somewhere between 60 and 110 mg/Dl in the fasting state, or early in the morning when you first wake up. 12.2 mg/Dl would be a very LOW blood sugar level, but 12.2g/Dl would be incredibly high, not compatible with normal health. If you cannot control your blood sugar you need to get a test done, maybe get medication to control it