I need some advice.

Some information about me:
I am a citizen of Australia.
I am currently outside of Australia with health insurance from the respected country.

My situation:
I am traveling to Europe in the next couple of days for 1-3 weeks before I go to China for business. I don't not know exactly how long I will stay in China. It is quite possible I will be there for longer than 90 days. Nevertheless it will be quiet unlikely I will be returning to Australia within 90 days. (I have already been aboard from Australia for longer than 90 days.) Does anyone know of or if a credit card or annual insurance policy would cover me in such a situation?

Do any annual insurance policy reset the 90 day period when visiting one country to another without returning to Australia?

Does anyone have any advice they want to share?

I have received quotes (online with the 10-30% discounts) to buy travel insurance for 3 months that would cost me around $500 which in my opinion is outrageous.