Struggling

So my baby will be 3 weeks old in a couple days and she's always struggled with nursing, so I've been pumping and feeding her that way. Well now that her intake has increased my milk has not 😞 so we tried to help supplement with formula, that didn't go over well...she ate it I thought awesome!  Help take some stress off me...nope not even 2 minutes later she had projectile vomit 🤢 not just some spit up full on had to change her clothes, my clothes, wash the two blankets that were on the couch next to me....Ugh