You seem to only thrive when you can oversimplify a point.
Before Nicaea there were a wide variety of ways in which different Christian churches saw Jesus in relation to God.
Some saw him as a DIVINE BEING
but not the same as God. Some saw him as a lesser-god type. Some saw him as only an inspired fully human man.
But they weren't heretics until one group decided that anyone who disagreed with THEM was going to be chucked out of the church.
That process of developing and agreeing on what was the actual faith took CENTURIES.
Not necessarily true. But it would require you to read a LOT more Church documents throughout it's history.
While I understand you are not a Catholic (that's the "wrong type of Christianity") but if you were to read through say "The Catholic Encyclopedia" from the 1920's (
HERE) you can learn a LOT more about the various councils, their history and the various creeds that were established over centuries which ultimately became standard Christianity.
Then you can read up on the history of Protestantism and how it attempted to break a lot of that in the 17th century. Then you can read up on how YOUR SECT was founded probably some time in the 1800's in the US (I am guessing here because I don't know what sect you are a member of).
Just know that what YOU think is "eternal truth" wasn't really arrived at 2022 years ago. It took centuries and centuries to come to you in its current form.