Gestational Diabetes 2

So, i went to the doctor yesterday, and found out my healthy active little girl, is 6 pounds 7 ounces and Im only 34 weeks + 6. Also have an increase of amniotic fluid as well.... they put me on Metformin but i feel like it wouldnt even matter because she may still be big either way. They say she would be about 8 to 8 1/2 pounds if not taken care of myself properly but thats so hard to do. I feel like... she will get big and i may have a c section. One thing i want to avoid. What are you guys opinion on what i should do? I dont want to freak out.