Teee, welcome to Psych Central. sorry to hear you are having a difficult situation with your commuter relationship.

One thing that you did not mention is kick the can down the road. Look for a job. Start making a network of friends and even a possible girl friend. See what happens.

The good thing is that she has made a decision - you are not giving her an ultimatum. She is. So you are free to explore other options and see what works out. if things don't work out you could return to Singapore but you may find the lifestyle limiting after experiencing Perth.

The fact that she is not discussing options but giving you an ultimatum, may indicate she is not the perfect match you think. Only you know. But someone that is inflexible can mean a lifetime of options limited by their inflexibility.

Here are articles that may give you clues what to do
Psych Central - Search results for Long distance relationships