Yes, good luck. Here's my experience, not in any way intended as advice!
I was diagnosed in the autumn of 2015. Having been "pre-diabetic" for some time, my HbA1c readings had finally nudged me into the diabetic category.
More as a matter of routine than anything else, I was put on Metformin, so now I have a magic card to get my blood pressure medication free as well, plus anything else I might need from time to time. Since one of the primary effects of Metformin is to "increase insulin sensitivity, thereby increasing peripheral glucose uptake" (Wikipedia) it seems plausible to me that it should have a positive influence on energy output. Whatever, within a couple of weeks of starting on Metformin I found I could ride centuries again for the first time in over a decade, and seemingly with greater ease than I can ever remember before.
My interpretation of a type II diabetic diet has been about as liberal as could be imagined. Nevertheless, I have lost over 15kg, so all things considered I must be doing some things OK. More worryingly, at my last review my HbA1c data had dropped below the diabetic threshold, meaning that I'm in danger of having to give my magic card back if it continues that way. So I may need to up my intake of pizza and cream cakes a bit to compensate for all the good things I'm doing.
The trouble is, nowadays I often find myself preferring the thought of stir fries and salads to pizza and cream cakes. So maybe my behaviour has changed for the good more than I realise.
When cycling, I use Asda's own brand Mars Bar equivalent when I need a quick energy boost, as I always did.