My Sugar Level Was 375 At 4pm And Within 3

My sugar level was 375 at 4pm and within 3 and a half hrs had halved. Not an official diabetic nor am I taking meds. I am terribly overweight and my liver values are around 100 but I figured it was bc I am overweight. But now I think bc my sugar levels are all over the place. Getting over bronchitis but just experiencing very high BP (M taking meds) and feeling lousy. Cd high sugar levels up my bp?