You need to tell your GP about your fears, and that you have been so worried that you have been thinking about getting a blood glucose meter to test your blood sugar, and that you want reassurance that your blood sugar is OK what with the anaemia possibly effecting the results.
Get your GP to explain what the criteria for diagnosing diabetes is, and ask what the normal range for blood sugar is.
Also, you need to tell your GP about all this anxiety, if you haven't already. Worrying all the time is not good for you.