Problems with theme update

Hello, Today I have updated Simple Catch theme to 3.5.7 version. When I've created my website, I have edited it with editor and CSS. Problem is now that I have updated theme and suddenly every customization I've made has disappeared. Is there any way I could undo it ? I also have Simple Catch-child theme, version 1.0 link: http://www.zupa-bezgresnog-zaceca-bdm.hr/ Thank you, Filip