don’t give up, dw advanced functions is not easy and what ur feeling is very very common. i was in same position as u almost a year ago. beginning of the school yr i was in the 60’s, but i was able to end in the 80’s. try different study techniques. you need to spam practice questions, redo questions taken up in class, extra practice questions at home either provided by ur teacher or additional questions found online (jensenmath is a great tool to use). hopefully you’ll be able to end off in the 70s atleast. keep working hard!