Truth exists. There is no such thing as “your truth” and “my truth”. These terms should not be uttered (except in rebuke) by anyone wishing to preserve the integrity of the concept of truth.
Incorrect knowledge is an oxymoron, not a type of knowledge. Being wrong isn’t any kind of truth, “yours” or otherwise. If we are strict with what we claim as truth, we will only cite that which we know with certainty. Logic is a tool for just such a purpose. All cats are mammals, Lucy is a cat, so Lucy is a mammal. This is true.
Subjective perception is also known with certainty, but that to which it refers is not. I see a tree - true. There is a tree - hmm... no. This you can never cite as certain knowledge. However, as per my other comment, subjective consensus can provide justification for using the word “truth” with some latitude, though only between people who know that when push comes to shove, it is not truth proper. This point should be established before allowing the word to be used for convenience in this way.
Truth is that which has undergone the formality of actually existing. That’s all.
RE: What is truth? The Ultimate Truth? Can someone truly lie all the time?