Here's my situation. How do I fix.

Girl and I cross paths, I get her name, make good eye contact, shake her hand. Then my mind starts moving very rapidly and I talk really jittery and make too many facial expressions. I make them laugh, then I say it was nice talking to you and walk away. I'm FLEEING.

I don't want to stand there in silence so as soon as run out of an immediate thing to say I flee. What are you guys doing? What do you do in the silent moments?