I have hyperglycemia, possibly developing diabetes my sugars are above 190 i notice that i'm struggling to walk even few steps away indoors, my legs and body feels heavy i get out of breath. i don't have pots, is high blood sugar affecting my walking?

With blood sugars in that range you are diabetic. The untreated and uncontrolled disease leads to multiple complications that require a full evaluation including tests to exclude heart/eye and kidney disease. Without a complete evaluation it is not reasonable to speculate on why you are having these symptoms. High blood sugar is just one indication you need to be evaluated.