My cat is healthy and hiding??

Hi, three days ago I came home from my new job on lunch break and couldn't find my male 2-year-old cat (I have two cats). I ended up finding him hiding in the bathroom closet which is two rooms down from my bedroom (he usually frequents kitchen, living room, and bedroom). He is a hider, but usually only if loud noises. I couldn't coax him out. He didn't eat or drink or use box all day. He didn't sleep with me (he always does). He now ventures to my room maybe once in the evening when I get home and uses box, but remains in bathroom and pantry areas through rest of day. I moved his food and water to pantry and he is eating and drinking just fine. He is loving, talks to me, is quite social when I'm in the bathroom/kitchen areas. In my room, he uses box, gets to my door, looks up towards the ceiling like he sees a ghost and darts off like he's scared to death every single time. Any ideas??? I'm very worried and if weekend doesn't fix, he goes to vet anyway.