I had a fasting blood sugar test last week, and the GP rang me this morning to say I have type2 diabetes. It is my own fault, because I am obese, I know - and I know that if I lose the weight, I could lose the diabetes too, but I am pretty depressed about it.
The thing to remember is that a healthy diet for a person with diabetes is a healthy diet for anyone else - low in saturated fat, low GI foods, plenty of veg. If you really want a cake, then have some with a meal - but you can have sugar, just limit it. Watch out for fruit and esp fruit juice as the sugar in fruit will still send your bg up.
Don't blame yourself for getting diabetes, but now is the time to really start getting on top of it, as you might end up thin and diabetic, but it does help.
If you come over to the Bootcamp threads, there are two posters there (MrsHerculePoirot and ChippingIn) who are both Type 2 diabetics, and they manage their condition via diet (low carbing). I'm sure that they will be able to help you!
Sorry that you're feeling depressed about it, but you can make things a lot easier for yourself with diet.