Does this sound right that I get Cold Sores inside my mouth?

I am a 19 year old college female. As a college student I tend to find myself stressing out a lot, thinking this caused canker sores in my mouth often, like 2 sores per every 2 weeks. Over break, I made an appointment with my doctor. After examination, she said they aren't canker sores, but cold sores. She said it is related to when I was 6 months old and was diagnosed with encephalitis. I fully recovered from that, but occasionally get seizures from that case, and now cold sores inside my mouth. She prescribed Famciclovir 1500mg at a sign of a break out, and Lidocaine Hydrochloride Oral Topical Solution(Viscous 2%) for temporary relief from the sores. Is this right that they are cold sores? I thought cold sores were fever blisters on the lip, outside the mouth?