Suggest Treatment For Gestational Diabetes

Hi I just got a test done and it was fasting, I am 5 weeks pregnant glucose fasting was 95, gestational diabetes screen was 170 my Hemoglobin Alc was 5.8 my ob Dr want to do a 3 hr test I had other pregnacy and never had these problem he wants me to take insulin, what can I do please help me I m very nervous and scared!