'keeps crashing' can you elaborate? Like, does your connection drop? Or is your client literally crashing, you should navigate to your latest.log file and upload it to a third-party paste service (e.g. Pastebin) so we can see what's happening when you're playing. There is definitely no reason on why you would be unable to play because you're from Australia, I am also AU and have no issue with connecting/playing.
Log files are typically found (assuming you're on Windows & playing on a normal distribution of the client via the Minecraft Launcher):
%appdata%/.minecraft/logs/latest.log (or whatever log is relevant; whatever date you were experiencing troubles on).
You should also double check you're network traffic isn't being routed through a proxy, and/or you're not on a VPN as this can definitely cause issues.
Note: be weary that your log files can contain your Minecraft session tokens depending on whether you play on a modified version or what not. Just double check your log has no sensitive information before posting anywhere.