First off you are for sure not a terrible mom! He may have a little bit of a low tolerance to dairy, if he's sleeping now and wakes up happy I wouldn't worry
I would wait a while to introduce something dairy again
Your baby’s way to young!!! There body’s aren’t made to handle all the proteins and minerals. You should hold off u til there around a year!! Currently have a six month old the most they should be given besides formula or breast milk is smashed fruits or veggies or baby foods!
Oh man was it milk based? Sorry I’m not sure about baby yogurts yet. If it was my kid I would’ve of kind of expected that but def if he’s throwin up a lot (not spit up but like forceful throw up) then I’d take him in