Overwhelming sadness when breastfeeding?

So this weekend we decided to hold off pumping (we're at my parent's place, and only have my hand pump for emergencies) and EBF to help baby latch. But I don't know if it's me being sleep deprived or what, but now at every feeding I just feel an overwhelming sadness. I rarely feel that way the rest of my day. Just during a feeding and a few minutes after. It's driving me crazy. I am leaning towards transitioning her fully to formula when she's one month old next week, but my fiancé insists he doesn't want to go fully to formula. It's super frustrating because I know it's his kid too, but honestly I'm the one who gets the brunt of the responsibility of breastfeeding. 😰 I'm at my wits end.