If he's vomiting food, it could be that he's eating too much too fast. My little Creamsicle does that and sometimes she doesn't even leave the food dish and she's throwing it up. I have to put a large stone in the center of the food dish so that she's forced to eat around it slowly, thereby causing less vomiting. If it's a lot of liquid vomit, especially dark liquid, it could be bile and that isn't good. It could indicate a liver problem. Take him to your vet and then you'll know for sure. Whatever the reason, frequent vomiting isn't normal and should be checked out. Since he's drinking so much, sometimes for as long as up to a minute, he could also be dehydrated from the vomiting or he could have early indications of a kidney problem. I haven another cat, Puddy, who drinks like that but she's in chronic renal failure. The hair loss could be because he's shedding his winter coat or it could be due to illness. Do your cat and yourself a favor and take him to your vet w/out delay. And please let us know what your vet says and how he's doing.