Everyone engages in textual criticism whether you know it or not. Every single person involved in "a" Textus Receptus was a textual critic. They all practiced textual criticism. Erasmus, Stephanus, and Beza! The King James Translators practiced textual criticism. Other KJV editors that came after the original ones changed readings practicing textual criticism. You yourself practice textual criticism. Just the most primitive form, whatever your particular edition of the KJV you happen to use you think it is right verses all the others.
You are a textual critic, because you had to choose one reading over another one. God does not want you to be in the dark about how the Bible came to us, nor is there any reason to be afraid of variations in the Bible. They exist. They happened. Even between different editions of the KJV there are variations.
You seem like someone that cares about Gods word. But if all you do is think that the KJV is always right even in the face of overwhelming evidence then perhaps not as much as it appears.
May God lead and teach you in his word.