How long after you had the blister did you do the first IgG test?
The IgM is notoriously unreliable, so don't pay any attention to those results - act as if you didn't have those.
Did they do a swab test on the blister?
Even if you do have ghsv1, the chances of you ever transmitting that are very, very slim. I've never heard of it happening. The only reason I'd suggest disclosing that to partners is to build trust. If you're with a regular partner, and a year into the relationship, you get an outbreak, your partner may not be happy that you never told them that you had this, even if transmission isn't really a possibility.
If it's a casual hook up, I don't see a big need to tell.