I'm diabetic too. I avoid sweeteners altogether these days, my doctors told me for what sweeteners do to you in the long term, you are better off using just regular sugars. Originally it was the aspartame in canderel. Then is was the Sucralose in Splenda. Long term these things are more harmful then just using regular sugar in moderation.
Thats why I switched to using a teaspoon of demerara sugar in my coffee, and only ever baking stuff rarely with sugars in it.
After my experience with the two previously mentioned, I wouldn't trust xylitol either, since both candarel and splanda marketed themselves on it being safe for consumption when they began marketing it, they had no interest in looking into the long term effects, and its only now we're getting the results of years of use from studies with the prior two.