I've no idea where UniSA is, and don't really think in terms of GPAs it's only a system really used in the USA and a couple of other countries. However 5.42/7 is about 77%, which suggests you're in the USA, as that would be an acceptable mark in most countries but the USA tends to over mark compared to most academic systems.
However, it's clear that you tried to do it your way, instead of their way. "They" being the people who have been running the training and education systems for years and know what works.
I think that your best bet by far is to go to your senior academic and flying tutors, tell them that you recognise that you've screwed up, and ask for their instructions for getting back onto track.
Then follow their instructions, without deviation, with a great deal of diligence and hard work, and without allowing anything else to distract you.
There is a risk, which you should recognise of course, that you may simply not be up to this. Some people aren't. But, you should be doing everything possible to prove that's untrue.
G