Diabetes and weight loss

I have lost over 70 lbs in about 2 years now. I still have 30-40 lbs that i want to loose. but the scale isn't moving now. I exercise like a mad woman because of my diabetes - I'm trying to " cure " it... Some days My fasting reading is 86 .. or like this morning it was 102. I don't understand why it is sometimes normal range when i eat over my 150 allowance of carbs a day and when i'm under my 150 allowance it's on the high end. I just got a elliptical. but before that i was doing arobics and walking everyday . 7 x week and would burn over 500 calories a day. doing my best to reach that 3500 calorie burn a week and sometimes going over that . I'm getting bummed! My mother was a size 0 . I want to be in that catagory . my diabetes would disappear. I do tend to go over my salt intake . it's hard sometimes not to. and yes sometimes i do go over my calories a day but hell the extent i'm exercising it really should be ok once a week? I eat fruit and veggies. i monitor my meat intake ..( if my husband wasn't so into meat i wouldn't be ) suggestions?