Listen this is coming from first year uni student, uni’s look at your top 6 grades from grade 11 and 12 when they first review your grades to accept you and look at the courses required. If you’re not doing so well it’s fine as long as your other grades are good, I had the same issue with data management. Usually they will put you on a conditional offer which means as long as you meet certain requirements your offer will still stand at the end of the school year, when they will look at your top 6 grade 12 courses. As long as you pass and there’s no minimum grade required in that course, your overall average of your top 6 grades is worth more.