duck diving help (bigger waves)

(i'm 14) So I can duck dive well and everything but sometimes when a big wave maybe 6 foot breaks on top of me or just before me (usually a dumper) I cant duck dive under a large wall of white water, idk what to do it really scares me, can i have some tips (running a short board) I can pop up well and can kinda turn but i get spooked when a big waves is about to smash me as i'm paddling my hardest. I just want to get out the back. Its just when I see it coming at me about to break it looks so big and powerful.