Woocommerce - all my normal pages are gone - please help!

Hi there, I’m really panicking right now. I got my website all settled yesterday. Really happy with the theme and all it’s possibilities. However, today I tried to install woo commerce and uploaded the Kaleb files. Now all the pages I made myself are gone. When I try to make a new one, I can’t do that, because the URL is being used already. Please help