Well, you need to get him something to eat now. He can’t wait. Maybe the shop will have some other type tiny feeders. Bean beetles, fruit flies, freshly hatched roaches, small black soldier fly larvae, baby silkworms, etc. Talk to the people at reptile shops, ask the person who you bought him from, do a search for on line feeder insect vendors. Your little man has zero resources to fall back upon. If he doesn’t get enough to eat, he will waste away quickly and die. It’s possible this is what’s already happening with his eyes being closed. Baby chameleons are little eating machines and should be getting well over 20 appropriately sized insects twice per day. Even call and ask your local exotics vet if they know where you can buy tiny feeders. This is urgent.