SSL Breaks WordPress CSS

We purchased an SSL certificat from network solutions (would never recommend them to my worst enemy, btw).

Apparently it’s activated… did a few checks that says it’s activated for our domain. But when I put in https://www.texasshredderclassic.com the entire site breaks.

I’ve tried downloading WordPress HTTPS, but that kicks me out of the admin page and also breaks the shit out of the CSS.

I don’t care if it works on the entire site, just need it working for our form page (texasshredderclassic.com/registration) – using gravity forms and connecting to authorize.net!

I’m tearing my hair out here because I don’t have a clue where to go next. Seems like we have the SSL cert… just can’t get the damn thing to work! Any help is GREATLY appreciated!