i had this and whilst it was a bit boring waiting for 2 hours it didnt go too slowly
i also came back as positive for gestational diabetes. they get you to follow a "diet", its not really a diet but a healthy eating plan really, making sure you dont take too much sugar. they also get you to regularly check your blood sugars. for most people modification of diet is all thats needed so quite straight-forward. you would need to keep checking your blood sugars (finger-pricks)
i had to inject myself with insulin, which sounds worse than it really was, very easy to do. and again, regular blood sugar tests. i had to regularly see the diabetes team to check my control.
most people are not positive but if you do come back as positive dont worry- the management isnt too bad at all.
ou have to have another glucose test 6 weeks after delivery if you are positive but its highly unusual for the diabetes not to have gone after birth
good luck x