Hello everyone! The baby started pulling everything out, we're a month…

Hello everyone! The baby started pulling everything out, we're a month in, it wasn't like this before. Now I raise him on a stool so he spits up, then spits up again, then spits up again with milk, sometimes even several times he pulls out ? He used to spit up once and sleep fine, if he doesn't spit up now, he wakes up after 5 minutes and does the same thing again. We alternate breast milk with formula. Formula only once or twice a day. We change clothes and the baby and me 20 times?? and the bed. There's also vomiting with an unpleasant smell, like cottage cheese... Sometimes without a smell. Should I be worried? What