Diabetic, need adivce please.?

I am going to get a confirmed test soon, becase I've been putting it off for literally 'years' - probably because I didn't want the diagnosis but I go to pee a lot, drink bottle after bottle of water and feel If I go more than a minute without water I'm dehydrating fatally, on top of that the worst bit of course is the fatigue which has been explained in terms of ailments ranging from Depression (which im being treated for) to burnout from a stressful lifestyle (which is also true) - so my question is finally, what do diabetics do about the fatigue? does it ever go away or get controlled by treatment? How can eating sugar free foods actually fight the fatigue when sugar/glucose is the main energy source in humans. Anyone with experience or diabetes, your thoughts.