My answer for you is this: The catechism, the part you quoted, is not meant for the people who are suicidal (their condition is different) but it is written for those who have either experienced people, loved ones, who are, or who have gone through with it. It is not meant to be taken in the way you presented, although I can see where it can almost seem to make one predisposed to give into that temptation. BUT ITS NOT written for those, it is written for those who do not or have witnessed and become distressed by someone else, usually a loved one with this type of situation.