Thanks to accusations that the Qatari Government supports terrorist efforts, many of the strongest Arab States that up til now had a good relationship with Qatar have done an about-face, causing a large diplomatic rift between them. This means no more flights to Qatar.
Emirates, Etihad, Saudi Arabian Airlines, Egypt Air and other Gulf carriers have announced they will no longer fly into and out of Doha, so if your tickets were booked with those carriers from Australia to Qatar, you're entitled to alternative options like full refunds on unused tickets and convenient rebooking. Otherwise thankfully, there will be little affect on the airlines' other routes, like those that connect Australia with Europe and Asia via Dubai.
Qatar has since been banned from landing any flights to Saudi Arabia, the United Arab Emirates, Egypt and Bahrain until further notice, in return.