Many inquirers have struggled in this area in the search for the truth.
Which TOC is the correct one since the various TOCs have declared each other to be in schism and/or in heresy?
First ask yourself: What are the claims of schism and/or heresy.
Take for example Gregory of Colorado. He has declared that his church is the only one that is left.
Gregory will baptize all who come to him, even if they were baptized by another TOC Synod, and then he will declare that since they were not baptized until this point, any marriages or clerical orders would be invalid before this baptism. In other words, a man could have been baptized, married, and ordained within Orthodoxy with or without children, and his ex-wife could still be living, and he could be allowed to marry (again) and even be ordained as a deacon and priest. Gregory would say that this man was never married before. This is strange and contrary to the teaching of Christ and the Apostles. Yet Gregory is not the only one who does this.
Even though Gregory seem to be free from heresy, he follows this strange practice of allowing second baptisms, marriages, and ordinations. In addition, Gregory's own past is checkered with schismatic acts as he left good synods, such as the ROAC and RTOC, without a good reason, which is a schismatic act.
So, forget him.
Look at Monk Kyrikos (formerly of the Matthewites). Okay, he still considers himself to be a Matthewite.
Monk Kyrikos was reduced to a simple monk for his heresies teaching that the Church is eternal, when the Church was born on Pentecost with the descent of the Holy Spirit upon the Apostles. He, like Gregory of Colorado, baptizes, marries, and ordains all who come to him regardless if that man had been baptized by another TOC Synod.
This happened when Bishop Seraphim left the GOC-A and joined Kyrikos. Seraphim was baptized anew, and then ordained as a deacon, priest, and bishop anew.
So, forget Kyrikos. Even if the entire world were to deny the faith, the Great Apostasy, as predicted in the End Times, I would not join Kyrikos or Gregory.