Feeling awful

I ebf my three week old and we’ve had a rough journey. From mastitis to thrush. Anyways I have noticed after a session I burp her and she spits up what looks like a great amount. This has happened with almost every session. On top of that she will latch for a few moments unlatch and cry. I don’t want to introduce a bottle but I feel like she’s spitting up everything she ate! I’m not sure what to do at this point. I don’t want to do formula just yet and her pediatrician is booked up. Please help!