The discipline I recommend above all else is self-discipline. No but seriously, when you're looking at the big picture like that it could be a little overwhelming and confusing. I say instead, set some short-term goals in a specific area and work on those. Having realistic short-term goals that you are continuously setting and achieving can give you that motivation and sense of accomplishment to keep you going. Take small steps as opposed to having this big massive overall life goal that seems like it's never getting any closer. It could give you that focus and drive that you need but again, self-discipline. Good luck.