Siberian Siren on "[Plugin: Contact Form 7] Contact form doesn't show in version 4.3"

I'm sure the theme was created correctly, but what I am saying is that I have customized everything within the theme, by modifying code in options.php, functions, etc...I don't want to lose all of that.
Wordpress 4.3 has already changed something with my customization to my home page. It will probably take me hours of work to figure out how to redo my customizations.