I would respectfully disagree with your doctor's advice. I highly recommend the following website for information on lowering your blood sugar:
http://www.phlaunt.com/diabetes/index.php
If your blood sugar was significant enough to put you on metformin, then you need to test to know how certain foods effect your blood glucose. How else can you know? It sounds like your numbers are moving in the right direction, and even so, you do need to get test strips and a meter and test a home.
I also note that you and I are the same height and you weigh less than I do. I strongly believe that diabetics and pre-diabetics need to test their blood sugar at home.
Congratulations on getting things under control.