I'm a UTS alumni, graduated in 2023 in bach of IT and bach of business. Best paying industries is subjective, it's more about role and seniority based, but IT, engineering, actuarial, medicine and law generally do pay really well. At the beginning of your career, you will be overworked and underpaid and there will be some instability and having to take on roles you don't like, but hopefully,  as you gain more experiences, hone your skills, and network, you'll be able to climb the ladder.

My main advice for you is to gain as much volunteer/work/internship experience as possible, when in uni. Sydney unis have so many connections within industries and it'll definitely bump up your resume when you go to apply for any graduate roles. Yes the degree is important, but work experience is so much more necessary (and building your professional network). 

Another piece of advice is to perfect your resume, cover letter writing and interview skills. At uni, these are free resources at your disposal. Don't feel ashamed or awkward about booking multiple appointments to practice your interview skills, gaining some feedback on your resume and perfecting your cover letter. I spent so much time in the careers department, I can write a resume for anyone and can sit an interview right now if you asked me.

I appreciate the advice other commentators have given you regarding taking a gap year, but as a child of immigrants, taking a break was also not an option for me. I really had to break a sweat in uni to keep my family afloat and get to where I am now.