Baby not latching anymore 😥

So after 12 weeks of trying to breastfeed and baby still losing weight, we went to exclusive pumping with breastfeading once or twice a day for bonding. Well, the last three days she won't latch. She actually cries hysterically. It breaks my heart, I thought we could at least have me be a pacifier or a little snack. And I didn't know the last time she nursed that it may be the last time completely. She had just started patting my breast with her hand as she sucked. I'm crushed. I know she may come back to it a little, but I'm still sad.