Maybe you should go through the Disability Support process with medical documentation and those that stipulate you cannot work in your original position at all. If you were a Mum on a Supporting Mother’s Benefit and studying you would be paid. High School students get extra allowance during school terms I know a student who was paid hess during school hoolidays than when at school during terms. If you have no other income you should be entitled to some support unless your assets or other income are too high.

yes you should be able to apply for a different payment though? if you are studying, it should be austudy payment, not newstart etc.

I suggest appealing to Centrelink. There are formal avenues for reviewing a decision, and if you are medically unfit for a role I can’t see how they could expect you to look for work in that area. Ask for a review, and consider taking it to the AAT if that is unsatisfactory.