You are correct in your discovery and assumption that your current 'circular' relationship will not work for this.
You will want to create a 'joined' table.
Call it something like "Joined Accounts"
Here is the tricky part:
You will want to make two relationships between Accounts and Joined Accounts.
Where one Account can have many Joined Accounts (twice)
Thus one of the connections will be Primary, and one will be secondary.
And you will have a record for any/all associated accounts.
Side Note: This isn't a 'chart of accounts' set up you are looking for correct? Because that is a different set up.
