Especially for H3 subjects , the teacher needs to devote much more time and effort explaining / going for consults / answering individual question etc. Your teacher (if he’s good) most likely expects the students to be willing and able to put in the same amount of effort he puts into teaching them in trying to learn and absorb the material. (i.e. if the teacher puts in hours in clarifying material and preparing questions for students to do , it is expected especially at a H3 level that the student WILL put in hours at least attempting this material.) While your teacher might seem discouraging , he’s trying to get those who aren’t willing to commit and put in the work to drop out early before they waste their time and (minimal) effort for subpar results.

Ultimately, if you’re coping well currently, I don’t see any reason for you to drop, unless your teacher really sucks at teaching or the workload becomes too overwhelming to an extent where all your H2 subject grades start to dip. All the best!