The fruit is very much like a hybrid of a Apple/Pear/Fig... Most closely resembling an Apple. I have looked up literally HUNDREDS of apples, and haven't found anything. Any help would be awesome!
That would be a Syzygium! It is related to Clove.
I would guess that it is Syzygium samarangense, or Syzygium aqueum or similar. My best guess is Syzygium aqueum, though.
Here is a source from the Purdue extension that will help:
Want to use it as a mosquito repellant
Indoors, you may need to add grow lights. Lemon thyme is suggested. The clove spice comes from a tree. These articles should help:
https://www.gardeningknowhow.com/plant-problems/pests/insects/mosquito-repelling-plants.htm
https://www.gardeningknowhow.com/ornamental/trees/clove-tree/growing-cloves-in-containers.htm
Will Lilly Pillys Christmas Bush grow in Blackwood South Australia
They should. They are very tolerant of most soil conditions. Here is more on their care:
https://www.gardeningknowhow.com/ornamental/shrubs/lilly-pilly-bush/planting-lilly-pilly-bushes.htm