Hey hscnewsyllabus! Welcome to the forums
So MX2 marks are always a bit of an "eh" for me when I'm talking to students - The fact is, you are doing one of the most challenging high school level courses in the country. It isn't going to be easy. Your marks might not be quite where you want them to be right now, but that's okay - Plenty of people have drastically improved their Extension marks from the middle of the HSC year, myself included
I think the big thing you should ask yourself is whether you are still getting satisfaction out of 4U. Marks aside, do you enjoy the process of learning these things? Do you enjoy the problem solving? If you do, there is no reason to drop the course at all! If you
hate the learning even without the marks, then it could be worth dropping. I guess what I'm saying is, take the marks out of the picture - Pretend you are doing your HSC for the
actual learning and not the numbers at the end (mind blowing, I know) and see how you look at things
Whatever you choose, this is the last point to make the call - Dropping a subject is really pretty pointless beyond the halfway point of your HSC. By Trials you've put in the hard yards, why give it up then!