This is my third pregnancy with GD. The diet isn't bad, you just have to remember to check your sugars which can be hard with little ones distracting you.
As for sweets and stuff - you can usually have a little so you don't feel deprived, but try to pair it with a protein and maybe later in day (my sugars are most sensitive in the morning).
My first I controlled with diet/exercise, he came on his own at 40 weeks. Second I was on glyburide so did lots of bpp's and nst's, and I asked to be induced the day before my due date. I had a crazy cold and could not handle being pregnant anymore,