Unfortunately, I'm not sure there's much you can
do without vet intervention and, therefore, more bills.
Mechanical problems like prolapses can be tricky to fix. If it were us, we'd probably head for the nearest veterinary teaching hospital--although pricey, we've had very good outcomes when dealing with their specialists. At the very least, a second opinion from them might not be too expensive and if they can offer no new advice there would be no further cost.
So sorry you're going through this. We've been in your shoes and it's a very hard thing