If he is normally an INSIDE cat… then he is definitely scared and hiding and you will need to go out at NIGHT with a flashlight and look for his “glowing” eyes. He is VERY CLOSE to your house… most likely in YOUR OWN YARD. Indoor cats usually find a hiding spot very quickly and very close to where they escaped. Look up in the trees and check under everything in YOUR YARD first… under decks, bushes, wood piles and sheds. Then check your neighbors yards. They are very good at hiding. THE BEST TIME TO FIND HIM IS AT NIGHT WITH A FLASHLIGHT AND HIS EYES WILL “GLOW” BACK AT YOU.
He is so scared, he will NOT respond to you calling him, so you'll have to use your eyes instead of your ears to find him. When normally inside cats are suddenly outside, they go into "survival mode" and their entire personality changes. They will NOT wander. They find a hiding spot very close by and are very scared and will not come out for anyone... even their owners.
I hope you find your fur-baby very soon!
Leave garage door open a little bit for shelter. Check the garage in the morning. Try to keep the windows open just a little so you can hear outside noises. My friends cat was an inside cat and showed up at 3 am outside the house meowing. They will tend to hide during the day because of all the noise. Put used litterbox outside. Check every hiding space outside the house, under porches, crawl spaces, bushes. Go out at night with a flashlight, their eyes will glow. Don't yell their name, they are afraid. I found my cat in the back of the couch, I had no idea he could get in there. I hope you find your fur baby.