Since I’m not familiar with Aussie laws regarding health records but I cannot imagine the Aussie folks couldn’t send the electronic pics of MRI to the U.S. docs. I suggest you get a fax number and secure email address for the medical record department of your doctor in U.S. Either obtain a formal request for medical record from Aussie hospital where tests were performed or send them a certified letter requesting that the info be sent to the docs with the contact info you obtained. Sharing of medical X-rays is the simplest thing to do when all the paperwork is correct.
You also need to give your neck more time to heal too and yes see a pain doc to get your pain under control. Do not expect to be in no pain. Consider it a reminder that you’ve got a bad neck and had surgery so treat your neck kindly.