Ahhh I feel for you both! Allergies boleh la jadi serious, especially kalau dia naik muntah dan kejang-kejang macam tu, definitely worth going to the clinic or doctor to check what triggered it and get proper meds, sebab antihystamine atau other medication boleh really help dia feel better faster lah. A few of my mum friends pun their husbands kena allergic reactions during pregnancy period, and once they found out the trigger (food ke, environment ke), it was easier to manage, so maybe try to trace back apa that he ate or was exposed to? In the meantime, make sure he's hydrating well and resting, and jangan skip meals when he's better because the body needs fuel; hopefully the doctor can prescribe something to ease the symptoms so he can eat and recover properly!