Why are you still there? Why are you still even in the vicinity of this woman? Why are you intercepting her phone calls and texts. You should have washed your hands of her before she even got back. Know why she's even in Australia now? Because back then you had a backbone and walked away. When are you going to say, "I'm done!" and mean it? She isn't going to choose you when you come off as a wimp. Who is she chasing? It's the guy that kicked her to the curb and has a new girlfriend...not the guy that kisses her butt. Get out. Get your own life. Forget about her for the next month. Put off her calls, texts, and e-mails. At least go dark gray on her. The first step is to get the heck out of that house. Pack right now and get gone. That's my only advice. There isn't any that involves staying there and continuing to look like the cuckolded husband.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer