I would check temperature and humidity--use a hygrometer/thermometer so that you can see enclosure conditions at a glance. Make sure that he has a hide or several hides available, with one facing the front of the enclosure, and cover the back and sides if you can. Field collected cane toads, especially those who are older and larger, can be very hard to settle down into an enclosure. He needs good enclosure conditions and time. The fact that he is eating even small amounts is a good sign.