what would you do ?

My baby is BF but my supply has dipped so I've been supplementing with formula. Well now LO won't eat formula at all. I've tried different brands but I'm not producing nearly enough. I drink mothers milk tea but can't eat the lactation cookies bc my LO has an oat allergy. I'm a FTM and I'm about to lose it. I'm so upset. I'm failing my baby and i don't know how to make things better. I tried power pumping. I tried pumping more often. I just can't keep up and now that he won't eat formula I'm on the edge of hysteria. Please please please any advice at all ???