Not secure? SSL Certificate from Bluehost/Comodo not working

Hi!

I am a volunteer for a nonprofit trying to figure out why our website is suddenly not secure. The site is hosted by bluehost, and we receive a free SSL certificate there for WP. Bluehost says the SSL is active. BUT This website: https://www.ssllabs.com/ssltest/analyze.html?d=languagethroughsports.org Says that the certificate expired 3 days ago.

I added the plugin Really Simple SSL. It said everything was ok except: “The mixed content fixer is active, but was not detected on the frontpage. Please follow these steps to check if the mixed content fixer is work”

I followed the steps including finding the mixed content fixer marker: data-rsssl=1 on the homepage.

On wordpress in the plugins it now says: “SSL Activated!”

BUT it still shows up as “Unsafe”. We have a fundraiser tomorrow!!! What should we do?

Thanks!

The page I need help with: [log in to see the link]