Hey there, I was experiencing issues with both my site loading and the Squarespace frontsite about 10 minutes ago. Per status.squarespace.com, which is where Squarespace will post about known outage issues, they are currently investigating connectivity issues.
I'd recommend keeping eyes on that site to see when it's resolved. Once resolved, clear your browser cache and then try viewing/logging into your site.
If their Help Center is down, you won't be able to reach their support team. However, you can always try visiting the Help Center through an incognito window to see if you're able to reach them that way.