You could have been misdiagnosed, or it is possible you are getting a false negative on the IgG test. I am going to assume you were diagnosed based on visual inspection only, and if this was the case, visual diagnosis is not reliable enough to go on. Your doctor didn't do you any favors; he/she should have swabbed the sores and pcr tested them.
Also, the hsv1 IgG test misses about 30% of infections and therefore, is very unreliable. The hsv2 IgG test misses about 8% of infections; much better than the hsv1 test but still not great.
If I were in your shoes, I would order a Western Blot herpes test kit from the University of Washington. As you may already know, it is the gold standard for herpes blood tests. It will help clear up a lot of this. I would believe the Western Blot results over a visual inspection.