I can help you disconnect your user in QuickBooks Online Accountant, Robyn.
When you delete a user, that action is irreversible, and the user's account will be permanently removed but you can still view their history in the audit log.
Here's how you can disconnect:
Head to the Gear icon, then select Manage Users.
Choose the ellipsis icon on the user you want to delete, then select Delete.
Click Delete user from the pop-up window to confirm.