Recall all the pain that made you want to ctb, then imagine all the disappointment you're likely to go through in the future. Condense all of these into a single day, as if into a ball of clay, and then pit it against the ordeal of catching the bus. This usually convinces me that ctb is the right course of action, refreshing my motivation for it. Overcoming the survival instinct is a different matter though, oftentimes all the convincing we tell ourselves won't matter much. I believe you really need a certain 'madness' to bring yourself to go through it without much thought. But I guess you already know all these, sorry couldn't be of much help. Just make all the needed preparations for your method, so that should the day come you suddenly feel ready, and enough to bring yourself to do it, then it's finally about time then.