Hi Dr Jess, I'm sorry to hear you're having a rough time with this. I can assure you that you can get a high ATAR with any combination of subjects — due to way the scoring system works the only ATAR you can't get most years without a subject that scales above 50 is 99.95. Everything else is achievable, even with lower scaling subjects. Additionally, note that your 5th and 6th lowest subjects (excluding English) will only contribute 10% to your ATAR — so worst case if you stay in and do poorly it may not drag your ATAR as low as you'd think,
If you do decide to stay in Specialist Maths then I'd recommend having a 1-on-1 with your Specialist Maths teacher about improvement. They see you multiple times a week and may be able to give some targeted advice on improvement.
Lastly, while it does feel horrible to struggle at a subject, I can assure you that you won't be the only one — even then plenty of people can struggle in school and still do fulfilling things after high school. Best of luck with whatever you choose. 🐢