You're confusing simple obedience with submission to the Magisterium; they're two completely different things. That's why the dictum "Faith is greater than obedience." is so pernicious. We have the Magisterium as our proximate rule of faith; that's what separates us from all the non-Catholic so-called-Christian sects. We can't have private judgment trumping the teaching of an Ecuмenical Council -- if legit. It's only based on a suspicion and positive doubt of its legitimacy that we can reject it.
I am not confusing anything, nor, though you say the contrary, am I the least bit confused about the two different things.
We all utilize our private judgement every time we sin and every time we flee from it. It does not matter from whence it comes, our first obligation in the matter is to avoid sinning. We all know what sin is and whoever doesn't know what sin is had best figure it out quick - they have nothing better to do, that is why we were all given brains.
If/when an angel from heaven, a member of the hierarchy alone, or altogether in union with the pope should teach a different Gospel, a Gospel contrary to what they've always taught, a Gospel they told us before the Council was anathema, St. Paul, presuming as he ought that we know our faith, says to let him be anathema, not "oh boy, we're in a real pickle here, what to do, what to do", or worse, "we must submit because the pope / hierarchy /council teaches it."
It is an historical reality therefore indisputable that the Ecuмenical Council preached and still preaches a different Gospel, so we cannot accept it's teachings - that's what St. Paul teaches because that's the way it works. It has nothing to do with our private judgement being superior to our superiors, i.e. the Council and hierarchy. It has nothing to do with that at all.