You're claiming defeat before you've even seen the battle, how are you so sure that it's not enough? It seems almost like the bigger issue here is your worrying, rather than knowing the material

If this is a re-take, then you should know from the first exam what areas you needed to focus on. Or were you too stressed to focus on studying? If you're too worked up to absorb what you're learning then that's where you need to improve - not trying to pile more information into your brain when it's not holding onto the first stuff

I agree with Basket, you've got to keep a positive attitude! It will genuinely improve your performance, I know from experience.

1. Don't think negative about the exam befor your done with it. Those negative thougths make it unnessery harder for you. You can puzzle about if you did enogth or not learn after the Exam. For now you did what you could do in the given situation.

2. Studying is not everyones thing. If you notice it not yours. Consider if there maybe alternatives aside of that corse of the university.

3. Regarding 2. your in this for some time. Scraping it is not so simple. Maybe you want to do your degree, but your so far unefficent in the learing. If that so, consider thinking about how to learn diffrently. (Like if you been alone, maybe learing in a group can help or visa vera?) If you want to do it there should be a path for you can go.

4. Probally nothing I say is useful, I never was to the university and I know if I had tryed I had failed and my head had exploded by now. >._.<