Please help me ladies😔

I am exclusively breastfed my 4 month old and i only want that, but suddenly baby wants to eat every hour and my mom kept telling me he's hungry, breast milk does not making him full, so i jumped for formula and baby doesn't want formula he constantly cry whenever i tried him formula, i feel so guilty for giving him formula i feel like my breast milk does not satisfy him, what to do please advice me, and he's diaper count is 4 wet diapers i change a day, and he pooped every 3,4 days later