WordPress 4.4.2 Cookies error after host updated to Php 7

I am receiving a “ERROR: Cookies are blocked due to unexpected output. For help, please see this documentation or try the support forums.” When attempting to login to my website at toppingcapital.com, additionally if you type in anything after such as “/testing/” or “/wp-admin.php”, there is an upload form?
I’ve searched and have already tried: resetting my theme, disabling my theme, disabling my plugins, through ftp. Checked my error logs, nothing to be found other than a hello.php error from 2015.

After discussing the issue with my host (hostgator) it turns out that they have upgraded to php 7.0 on 03/31/2016, 2 days later I noticed this login problem. Could that be the root of the problem, and how would I go about fixing it?

Thank you!