My son got exposed to Herpes Simplex 1 when he was just shy of 2, when my mom kissed him while she had a blister. He had an absolutely TERRIBLE outbreak, and I was really upset.
I scoured MDC and found lots of posts about using Lysine at the first signs of a outbreak (or ongoing), as well as Grapefruit Seed Extract during an outbreak. Other than that it's mostly about boosting the immune system. There are also some homeopathic Apparently something like 80% of adults in the U.S. carry this virus, so it's very common.
Here is the link to my previous thread about this topic:
http://www.mothering.com/discussions...ight=cold+sore
You can find other topics about this by searching "cold sore".
Good luck! I know how much this sucks, but my son has not had any outbreaks since the initial one in February, and I understand that maybe people do not have subsequent outbreaks after the initial one.