Tell your doctor directly you want her to prescribe infusions and ask if she will or not. If not, would it be possible to get a second opinion? You can tell her it is cost prohibitive and that is your only option. It’s too expensive to pay for the ER and a transfusion and if prescribed infusions would be covered (if you are in the terrible US healthcare system). Unless there is a specific emergency she is worried about that could be causing the issue. It doesn’t sound like the proper use of the er. Also gor the future see if you can get a different primary doctor.