As important as the events in the Garden of Gethsemane were, they receive very little attention in scripture. Matthew has 11 verses on it, Mark also has 11, Luke has 7, John tells us nothing about it at all, though he was as close as anyone to what happened. The Doctrine and Covenants has 4 verses about it and the Book of Mormon 1. Why do you think the scriptures are relatively silent about such an important event? Does that tell us anything about how we should understand what scripture is or is not?
Here is a link to a document with a side-by-side comparison of all of the scriptures about the events of Gethsamene.