Discouraged

Last night my CGM alarm went off at least a half dozen times due to low blood sugar. Each time I took a glucose tablet (chocolate milk once) and went to sleep. This morning my readings were low still, about 60 and I checked with a finger stick and the reading was 101. Now I’m thinking all the readings last night were in error. I’m not sure why I’m paying for a CGM when they are so unreliable. What am I doing wrong. I calibrate about three times a week.