It's a complicated subject.
Sorry for missing your question.
Sorry for your frustration, also. But it is a very complicated subject, and many do the Word of God an injustice when they try to simplify it. (Not saying that you are.) I've studied the subject since preparing for our first furlough from Japan in 1985, and am still learning. At that time I came up with a 19 page outline.
1. God's Word is forever settled in Heaven.
Ps. 119:89. For ever, O LORD, thy word is settled in heaven.
2. On earth, God preserves His Word through providence--in other words through human actions that He guides. I know of no earthly miracles recorded showing forth the preservation of God's Word. Can you tell me of one?
a. "Thou, even thou, art LORD alone; thou hast made heaven, the heaven of heavens, with all their host, the earth, and all things that are therein, the seas, and all that is therein, and thou preservest them all; and the host of heaven worshipeth thee" (Neh. 9:6).
b. "For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or power: all things were created by him, and for him: and he is before all things, and by him all things consist" (Col. 1:16-17).
c. One of God's names is "Preserver" (2 Sam 22:3, Job 7:20).
3. We humans are responsible for the preservation of God's Word on earth.
In the OT, the priests were keepers of God's Word, the Law. We are priests in the NT age, so we are to preserve the Word.
Compare:
Mal. 2:7. "For the priest's lips should keep knowledge, and they should seek the law at his mouth: for he is the messenger of the LORD of hosts."
1 Peter 2:5. "Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ." (And other passages.)
4. As a believer, I am working to be God's servant in the earthly preservation of Scripture.
Matt. 28:20. "Teaching them to observe all things whatsoever I have commanded you."
Jer. 50:2. "Declare ye among the nations, and publish, and set up a standard; publish, and conceal not." (And many other passages.)