why did bilbo age so drastically yet gollum didint

[Lord of Angmar]

*** Do not confuse the movie aging of Bilbo with that of the books. In the movies, Bilbo fell apart in the span of seemingly only a few months.... and a year later he was almost dead. ****

Yes, that is a very good point, since a 17-year time gap between the Long Expected Party was never even implied in the movies. He did have more than four years in the movie to reach the final dicrepid state he was in in the Grey Havens scene, but that is not nearly as much as in the books.