in my point of view 6.8 is in the diabetic range, but low temperature in the morning and if feeling exhausted , there is a risk of being hypothyriod, that is having too low a metabolism which also can cause a slight raise in blood glucose and make it very hard for people to loose weight, but that is a doctors job to find out..
if ones insuline works like it should , it will always try to counter-act the raise in blood glucose, when it is getting too high, so lower blood glucose can be a very normal reaction to eating something that raises ones blood glucose very much, so nothing unnormal in that...
if you want to know for sure if you are not diabetic or if you are diabetic, you should go to your doctor and get a HbA1c blood test, which finds out what your average blood glucose has been the last 3 month, that is often a very sure way to find out if one is diabetic or not...or maybe pre-diabetic, where one also has to take lowering of carbs very serious..
wish you all the best of luck with your Health but do go to the doctor to get a proper diagnosis instead of just guessing here... we can never give you a diagnosis, that is not anyones job in here , and would also be iresponsible of any of us..