Sometimes you have to push yourself even if it means being harsh to yourself. Just don't be too negative towards yourself. Keep yourself accountable, but no need to self-depreciate or lower yourself down as that only makes it worse for some people.
I mean to be honest, if you're not harsh with yourself now, when you fail to qualify the exam, you'll feel even worse. So why not just tough it out now?
Start with one small habit or thing that gets you out of your comfort zone and not a whole routine change. Remember that you're going to have to unlearn what for the most part is an automatic habit at this point. And when you get the uncomfy feelings, confront them and think about them and acknowledge them while also reassuring yourself that the discomfort will go away with time.