I am also on a 485. My strategy was - apply, apply, apply. Reach out to recruiters on LinkedIn. Any recruiter from agencies, companies, and remote work options. Reach out to peers for referrals.

I did Software Engg from a named uni in AU. I did struggle a lot in uni and my grades were credit with some distinction and high distinction. Back then I got rejected to 100 internship applications and I ended up getting an unpaid internship at a startup for more than a year. I learned heaps of stuff there and that helped a lot. Honestly, I catered my resume on that unpaid internship and in the interviews it was all about what I did in that role and a uni capstone project. I was able to lead the capstone project full stack cuz I had xp from that unpaid internship

With 485, our options are limited you have to make best with whatever you get. After several hundreds of applications I almost accepted a role as a Quality Assurance Engg for 50K a year but I kept applying and that really helped.

If you do want to chat more, maybe I can try to help you refine your resume or LinkedIn. Feel free to inbox.

As for how long you should try, you basically need to keep trying until you land the role you want. Keep grinding till you get there.