Boyfriend has been throwing up for almost 2 weeks

Hi, my boyfriend used to smoke daily, morning and night. He started getting nauseous 2 weeks ago but brushed it off and we did shrooms that night. Since then he hasn’t been able to smoke and the doctors told him it was CHS. He’s been throwing up multiple times a day for almost two weeks now and barely eating. He’s has gone to the ER multiple times but they don’t find anything wrong so they just give him fluids and nausea meds but after he’s out of the ER he slowly starts feeling worse again and the cycle repeats. Is this normal for CHS to be this aggressive for 2 weeks? I’m really worried