3 week old-vomiting and smelly gas

Since this AM my 3 week old has been throwing up after every feeding.

I fed her formula this AM at abuot 5 am. Then my husband fed her at 8:15 ish. Ever since the 8 am feeding she’s been throwing up after each attempt to feed. Shea are about 8 ounces total today without throwing up after them. The rest of the feedings she’s thrown up shortly after. She threw up like 5 times today. The 3rd time she threw up it was yellow, like bile.

Now it’s about 1015pm and she’s farting like nasty smelly farts and her poop is smelly too. I never knew newborns poop smelled bad.

She is also breastfed. These last couple feeding attempts have been breast milk and she’s been fine so far.

Has anyone experienced this before? I will keep monitoring to make she doesn’t get dehydrated.

TIA.