Hi Cupid,
I don't where you got your information from, but the book of Revelation kills that idea in the very first verse of Revelation:
"The revelation from Jesus Christ, which God gave him to show his servants what must soon take place. He made it known by sending his angel to his servant John, who testifies to everything he saw—that is, the word of God and the testimony of Jesus Christ."
The word "apokalupsis" translated "Revelation" is defined as:
("revelation, unveiling") is principally used of the revelation of Jesus Christ (the Word), especially a particular (spiritual) manifestation of Christ (His will) previously unknown to the extent (because "veiled, covered").
God gave Christ this information and he sent his angel to John with this information contained in the book which was a disclosure of truth, instruction, concerning divine things previously unknown. Therefore, it could not have been written 200 years or more before John received it. This also means that Jesus could not have only supplied the first three chapters and that because he was given this information to John to show him the things which must soon take place, namely, the seals, trumpets and bowl judgments of God's wrath, as well as the rest of the information contained therein. To be clear, some of this information was only known in part by the prophets as "the day of the Lord". The book of Revelation is a detailed account of the day of the Lord, that time of wrath.
My sincere advice to you is to stop getting your information off the internet and stick to the word of God, because Satan seems to be using that as venue to distort God's word and many are being led astray by these false teachings.