Yes its easy to think about motivating yourself but when it comes to practice its a different story. You just need to be more firm with yourself and realise , like what your doing, about the future, that if you **** these up, then what? But if you pass, you have ten times more options maybe.
In business there's a rule called the 80/20 rule. This is how you could relate it to this issue, i think! (ps this rule works so that the 80% input means you pass the exams and the 20% relates to not doing so well)
Put 80% of effort into your studying/exams and then in the future getting a job will be 20% effort = easier with tonnes more options and opportunities and you'll not have to work so hard
Put 20% of effort into your studying/exams and then in the future getting a job will be 80% effort = harder due to lack of options and you'll have to work ten times harder to get a decent position or work your way up a company.