The symptoms that you are experiencing of a red spot and tingling could definitely be the start of a cold sore, even if you haven't had one in years. Yes, you could start the Valtrex
, and the recommended dose for cold
sores is 2 grams, then 12 hours later, 2 grams again.
Your concerns about your family, though, are interesting. If you simply avoid kissing people when you have a cold sore, you won't pass this virus to them.