On Android Work Gmail Account synching to my personal gmail and that of a coworker and we are getting each others messages, how to stop please?

Okay, so sorry if this isn't super clear but here goes. I have a work gmail, and me and my coworker synched our personal gmails to this account through our phones. Now we are getting each others contacts, messages, etc. I need to find a way to stop this from happening. I haven't been able to get a direct answer on how to fix this. Any help will be greatly appreciated .