What would you do?

So recently my EBF baby has been spitting up everything she’s eaten right after I feed her, and then she’s hungry again. I haven’t eaten anything I’m not supposed to, no dairy, cabbage, onion, etc I don’t know what’s wrong. And to make matters worse, even though she’s starving, I can’t feed her because it’s literally RIGHT after she’s already eaten and I haven’t produced anymore milk. I don’t want to give her formula, but should I? I don’t want her to be hungry constantly. But the thought is making my PPD worse and I don’t k ow what to do. The thought of not being able to breastfeed is devastating, I thought I was prepared for that possibility, but I guess not.