About a week ago my cat seemed physically injured. I picked him up, and he screamed like he was hurt. I put him down and searched for any visible injuries on his body, and couldn't find any. He didn't move much that day, but the next day he seemed 100% back to normal. About 3 days ago, he started acting like he was sick. He wouldn't move from the spot on my bed, he was sneezing, he wouldn't eat, he wouldn't drink. Something was definitely off as he wouldn't even eat tuna when I stuck it under his nose, which he usually goes insane for. Yesterday morning I put water under his nose and he drank quite a bit, but still wouldn't eat. I took him to the vet that day, and they couldn't find anything wrong with him. He didn't have a fever, he didn't seem dehydrated, the tests for feline leukemia and others were all negative. They gave me some antibiotics to give him just in case and sent me home. Today, he's acting waaaay out of character. He started walking around the house more, but as far as I know still hasn't eaten anything and won't drink anymore. He's acting like he doesn't know what anything is. Like he's seeing things for the first time. He almost seems like he's hallucinating. He stared at a rug, while constantly moving his head in a circle like pattern, looking like he was going to fall over, for a solid five minutes. He then did that to a basket, the laundry drier, and other various things. I've never seen ANY cat act like this, much less him. It's unsettling to watch, and I have NO idea what's wrong with him. Still won't eat. I'm calling the vet again tomorrow. Any ideas?