breastfeeding

my breasts feel very soft , i don’t feel ‘ let down ‘ that much anymore !?!?! when i pump the most i get is 1.5 and i’m lucky if i get 2 oz from from breast !! i feel like my supply dipped i went from pumping 5oz each breast to now this little bit that i’ll scream if any gets wasted i want to breast feed for at least a year but i’m so worried my supply is going to dry up , i have to supplement which i hate that i do .. any advice to boost my supply ??? my baby will be 4 months in 5 days