Can’t Access wp-admin after attempting WP upgrade

Ok. I recently went to update my wordpress from 4.6.1 to 4.7, and during the update I was booted out of the admin and haven’t been able to get in. Every time I go to my wp-admin access, I’m met with this url: abfilmreview.com/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F making it impossible to login.

To make matters worse, I foolishly decided to migrate my hosting service to a new provider the night that this problem arose. I’m unsure whether I’ve exacerbated the problem or not.

I have moved my domain and hosting to a new service provider, and have waited to see whether once my domain is registered that may help with my login issues, but no joy. I have cleared my cache on Cloud Flare and my browsers and still no joy. Through the assistance of the new service provider, they have been able to login to my wp-admin by disabling the plugins folder – but when I try that, I’m still met with the same error.

Can anyone assist in finding out exactly why I’m unable to access the wp-admin but they are? I’m starting to get a bit anxious about the possibility that I’ve really screwed myself up with the access to my website and just want to have it all fixed.