Can’t access wp-admin dashboard

When my host (A Small Orange) changed a policy, no longer allowing access to accounts in this manner *https://1.1.1.1/~username*, it inadvertently cut off access to two of my blogs’ admin dashboards.

In other words, I used to go here:
https://server.ip.address/~username/wp-admin

and now I need to go here:
https://mywebsitedomain.com/wp-admin

But when I try that, I get a 404 error.

What’s the best way to get access back?

I have both FTP and cPanel access but frustrated that I’m cut off in WP.