You should set rel alternate hreflangs on both sites -
<link rel="alternate" href="http://example.com.au" hreflang="en-au" />on example.com
<link rel="alternate" href="http://example.com" hreflang="en-us" /> on example.com.au
then you sholud set targeting site content to a specific ...
Your total time for DNS is 486ms, which is OK. So the loading time issue is not with the hosting: http://prntscr.com/uw69rh
You need to optimize your site for a faster loading. It looks like getting rid of the Fontawesome alone can save you a massive 2,580ms: http://prntscr.com/uw6bd9
So start with that. Replace all of your icons with inline SVGs. Then ...