So here’s one way to look at it when a book/series you enjoy is being made into a movie or a TV show. No matter what happens with the screen version, the books will ALWAYS be what they are, and were for you. No movie or television show, good or bad, can change that for you. So instead of worrying whether the movie or show will change the book (for better OR worse), think of the exposure it’ll generate for the book. Sure, not everyone who sees the movie or the show will run out and grab the book, but they’re probably not people who were likely to discover the book on their own in the first place. But there may well be people who see the story or the characters on the screen and DO go pick up the series, and that can only be a win for fans. More people you can talk to about it, right?
(And if all else fails, you get to be a book/series hipster. After all, you loved it before it was cool.)