Welcome to the Forum and, most importantly, welcome to bike riding. I am a diabetic too. By riding my bike, and careful dieting, I have been able to lower my A1c from 13 to 5. (Translated that means that before getting on my bike my daily BG averaged nearly 300, now it averages less that 97.)
You don't have to go all-out to see improvements on your numbers. Regular bike riding and some other form of aerobic exercising, plus sensible riding will do it. The September issue of Bicycling magazine has a really good article on losing weight by riding your bike.
A diagnosis of diabetes can be pretty bad news. But you can beat it. I am sure that I am not the only diabetic on this site who can attest to the power of bike riding in controlling diabetes.
Send me a private e-mail if you need advice or if you just want to talk about it.
Good luck my friend.