So let me be certain I have this right: you had an IgM showing HSV 1 antibody? That is not adequate to determine that you are infected with HSV 1. The IgM test is wrong a very large percentage of the time. Whether you have a cold sore at the time or not is not relevant to the results of the blood test. I would say if you get another cold sore, get it swab tested to see if it is really HSV 1. The most reliable test for HSV 1 is the herpes western blot. The IgG test for HSV 1 misses 1-2 of 10 infections.
I am also not convinced about his cold sore status now. Are you?