Failure with breastfeeding

My baby is 3 weeks old. I formula fed my first because he wouldn’t latch. My daughter latched immediately but my supply dropped significantly even though she breastfeeds every 2 hours. I went from making 4 oz to making 1/2 oz per breast and my daughter is starving so I ended up supplementing. I feel like I failed for a second time. I wanted this so badly because I couldn’t breastfeed my first an sadly I live in korea where there is no where to get anything to boost milk production, not even flax seed or brewers yeast. I am beyond sad and ended up breaking down crying in the middle of the store. My daughter prefers the boob but since barely anything comes out she gets overly mad. 😭