Why did Bella jump off the cliff in new moon?

During the book New Moon by Stephenie Meyer, the character Bella contemplates the idea of jumping off a cliff on page 358, but actually jumps off on page 359. The chapter where it happens is called Pressure. I checked this information out, and who ever wrote this is exactly right, just thought you should know incase you thought it was a spam. you should totally read new moon dont skip it i did and now i am confussed