Welcome here to the Forum, and I think your choice of future career says a lot about you. I also think your reaction to less than perfection says a bit more.
I was a uni educator for very many years - even took nursing students for one non-medical unit they had to do. The number of students who sail straight though their course to a degree without any hiccups is surprisingly small and the procedure after a failure is well established.
It can be inconvenient if a subsequent unit depends on that one, but is normally easy to sort out.
So go see your faculty or the counseling unit . If there are extenuating or medical circumstances you should explain them. It is possible you might be entitled to special consideration. (COVID related matters may have been an undue influence for example) and can be re-tested
Otherwise it most probably simply means you repeat the unit and this time, between what you have learned already and getting timely help as needed (perhaps a study group, perhaps a tutor or special extra work the lecturer might give) means you will pass next time. It is not as if it was a terrible failure after all.
The most complicated thing will be finances, and I'm not sure what the HECS arrangements will be 2020-1
In some ways a study group might be another help, you sound as if you are trying to deal with this all on your own, is there nobody to talk things over with, fellow students, family or a freind?
You are always welcome here