Of course you haven't divided the Body. No heresy ever has.
Dear Brother Catholic,
There are no heresies taught by my Church.
Which ecclesiastical organization would that be?
None. So I agree with you fully.
If that were true, you would be under the omophorion of a bishop in the Orthodox diptychs of the One, Holy, Catholic and Apostolic Church. Since you are not, that cannot be true.
In fact the worst of the heresies that we were required to struggle with over the centuries came to us full blown from the east.
Ultramontanism came like a blow hard hurricane strength, with swords, from the West. As for those which came from the East, like Arianism, we didn't have to struggle with them for centuries (Arianism was dead in the East in 381, killed by St. Athanasius, who came from the East, and the Fathers who wrote the Creed, nearly exclusively a project of the East) as they died out within a century (Nestorianism being a rare exception, and it had to go far East to survive), whereas they found fertile ground to florish in the West (living on in the far West of Spain, homeland of the filioque, another heresy).
Christianity came from the East, founded in Jerusalem, not Rome, revealed in Greek and Aramaic, not Latin.