First of all calm down.
It sounds like you disabled the ACL mechanism. So yes everything defaults to open and there is no way to log in anymore.
This means you need to (re)configure DokuWiki by editing the config file conf/local.php
using a text editor on the server the wiki is installed at.
If you don't know where that is, or how you access the server, you need to ask for help. That help might either be your IT department (if the wiki is running on a server managed by them) or your hoster (if you are hosting the wiki on a public webserver, which is unlikely for a corporate environment).
BTW: Once you got the wiki back on track, your company should think about what place the wiki has and what measurements should be taken to avoid things like that in the futrue. That might involve outsourcing the hosting, getting a SLA with soemone familiar with DokuWiki or maybe some training for your and your fellow co-admins.