Hi Michelle,
You can definitely change to the public system. The referral to get your seroma drained is transferable to the public system. Its a common procedure, and many public hospitals have a 'no gap' policy for those with private insurance. Or just say you don't have any. Get the referral sent to your nearest public hospital or get a print out and make your own appointment. Just ring the medical imaging department and they will sort out a time for you. It may be a little inconvenient as far as booking a time is concerned, but that is the trade off.
I don't know what arrangements you have made regarding paying for your radiotherapy, but have that discussion today and say you can't afford any more out of pocket costs. You can negotiate these things and never feel guilty about haggling.
The BCNA people will be back on deck on Monday, give them a ring and they can provide some advice on navigating the financial minefield. Hang in there, seroma and infections are awful and carrying that toxic load in your boob affects every aspect of your life. it makes you sick. Once you can get on top of that issue you will feel a bit better but, unfortunately, having to force yourself to go to work when you are unwell doesn't help the healing process. It sucks you have no choice. Good luck, Marg
