Hi CeeCee, I have no idea what the South Beach diet is but I do know that you will be diabetic for the rest of your life and any diet that is designed for people to use short term to loose weight will not be tailored for any individual to eat for the rest of their natural.
I would recommend that you find out through testing what foods you can manage in what quantities and design your own lifestyle around what you are able to eat whilst comfortably controlling your bg levels, no diet designed by anyone else is going to do that for you I'm afraid.
Test test and test again until you know what you can eat.
Sorry to sound so negative towards 'diets' but thats just the way it is, everyone has to find their own diabetes lifestyle path to follow, what works for me almost certainly wouldn't work for you and vice versa.