Low blood sugar problems? Need advice!

Is anyone else having low blood sugar issues all the time? Some days are better than others but I can't even go to the grocery without almost passing out.  I even eat before I go!  The doc said its normal but some days I have blood sugar issues ALL DAY! It's as if for every 10 productive minutes I have, I have to spend 20 minutes sitting and resting to keep from passing out!  Help!