Ah, I'm so sorry. It does sound like he freaked out. But give it a few more days, he should come around.
In the meantime try appealing to his curiosity to get him back to his cage. Do you have a bunny carrier? If not, use a box.
Most bunnies can't resist going inside. (or put a treat inside to entice them. Once inside, quickly but gently close the box. Try not to shove your bunny in if he's only halfway in, otherwise this will never work again. It needs to be a pleasant experience. Then you can take your bunny over to his cage and let him go from the carrier to his cage or pen on his own. While he is going from the carrier to his cage, say a key word or words like "home, home" or "Go to your cage", I know it sounds kooky, but over time most bunnies will associate the word with the meaning. My own bunnies now go to their cage with little herding when I say "Go to your pen"
Once he' s in his cage, give him a treat there.
Let us know how that works.
Tip:You can also say the "home, home" or whatever you choose when you are herding your bunny back.
In the past while I was herding them I'd say "Go to your pen". In the beginning it took a while, (don't ever chase, just follow and follow) Most of the time they get tired of it and finally find refuge in their cage or pen. As soon as the bunny goes in, I give a treat and back away. That way it's not punishment, and they get two positive things: Left alone from following and a treat.