I completely understand that reaction. It is the same one I had while watching the first two movies in the Lord of the Rings trilogy. At least until I made an essential bargain with myself, with help from the great J.R.R. Tolkien.
You see, Tolkien wrote the Middle-Earth stories in character, meaning that he wrote the material as if it were from historical documents. This was made evident when he went back to The Hobbit to change and add to the story of the One Ring, which had originally lacked the significance it would later possess in Lord of the Rings. He justified the changes by saying that it was based on more accurate historical information.
When I learned of this the light bulb went off in my head.
In the spirit of Tolkien’s original vision, why couldn’t I as the reader and viewer absorb the adaptation in this way? Perhaps Peter Jackson found historical documents that contradicted the information in the books. Tolkien was working off the hobbit version of history, while Jackson chose the human perspective. That would explain why Tolkien covered more of the hobbit’s plight (Scouring of the Shire), whereas Jackson had a more cynical view on some of the human story lines (like Faramir’s). That doesn’t mean the movies had more accurate information, just different. I could still prefer the Tolkien version of events but without completely discounting Jackson’s material.
I then thought I could do this with any adaptation of any book. If great master Tolkien could do it, then everyone should be allowed. Therefor, “Thrones” show runners David Benioff and D.B. Weiss aren’t raping George R.R. Martin’s masterpiece (mind you, Martin himself has also made adaptation changes in his own episode scripts). They are interpreting it based on different historical documents snatched through a time portal between Westeros and Earth. Perhaps these documents were written by Lannister historians instead of ones from House Stark.
Worst case scenario, once you digest the different perspectives on the (faux) history you love, you can always dive right back into the written word and believe it to be the correct version. Until then, enjoy the adaptation. It’s actually quite a wonderful experience --if you let it.