Cold Sores? I know an odd question but every time I get stressed out I get a cold sore on my upper lip that makes my lip look twice as big as it normally is (my lips are normally big). I have always gotten them since I was a child it's a genetic thing so my doctor says. Like right now I have been stressed with us moving into our first official place together in a week plus the wedding in a month. I am just worried about getting one right before our wedding & either my lip being huge or it's scabbed over. Does anyone know how to prevent a cold sore from coming?