upgrading also broke my site

Thank goodness for backups. I had to revert to before the upgrade. I lost all access to my network dashboard (except for the Jetpack settings, lol). I was absolutely unable to access anything else. I have no idea what the problem could be. I’m using Multisite and SSL, in case that matters. I kept getting a “too many redirects” error.

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