What are your experiences on GDM?

Nati • My description, your challenge
So I took blood work & got abnormal results for gestational diabetes. Im really scared, how would this effect the baby. Im going to take another 3 hour test tomorrow to confirm it but im really depressed and scared for my baby & me. Can anyone give me a little more knowledge as to how bad gdm is and what exactly it is?.. With my 1st child I was normal why get it now??