I am going to present you with a cure for all your problems.
Coconut oil kills lipid-coated viruses on contact. Now cold sores are caused by a member of the herpes family of viruses, which are lipid coated. So coconut oil kills the cold-sore virus on contact. Apply it topically as soon as you notice the tingle, and the coldsore should never appear.
If you like you can take coconut oil orally for preventative purposes.
I tried it about 6 months ago on a coldsore and the coldsore didn't even appear!! It worked like magic. Its been 6 months and I'm still waiting for another one.