It's a dreadful shock to be diagnosed. It happened to me in December 2012, just before xmas.
Thankfully, there are a lot of resources online to help you figure out how to deal with it. It is very daunting.
The main advice I'd offer is this:
Find out what works for you.
There are some very low carbers, low GI or high protein dieters here on the website, and I've found that it is best to get a meter and some strips, and slowly work out a diet that works for you, then stick to it.
Sticking to it is the hard part, once you have regained control. Many of us have fallen off the wagon, and got back on again etc etc. Without a meter, you can't tell how you are doing, so let that be your guide.
Good luck

It's not all bad, it just means you have to pay more attention to your body and it's reaction to what you put in it.