What a situation you are in. Wish I could do something or offer something to help. Whenever my buns stop eating I get fresh hay and tap their noses with it. This basically annoys them and they lunge at the hay taking a bite. Keep doing it until they eat. Its a small start but at this point its worth a try. Have you tried gently massaging his tummy?
Be very careful with what "unknown" medication you give your bunny. And do not always rely on the Internet for valid information. If you can get a rabbit health book. If they are not available in Japan try Amazon. They have plenty of choices.
Oh my God that worked. THANK YOU!
He is slowly eating his grass, drinking on his own and taking the vege juice.
He randomly peed on my floor in a few places and he never does that so I was a little concerned. I'm still watching to see if he poops. It is almost 3 am here, but I will report in the morning.
The vet said if he was not eating I should bring him back. If I did that, I would have had to take him to work and stick him in a carry case for 8 hours and I don't want to do that. Do you guys think I should report back to the vet if he is eating in the morning? I can still hear him grinding his teeth.