He switched locations 3 times: from small cup, to a vase, to a decent tank. He is probably stressed like crazy.
Make sure your tank has a heater, decent filter, and light. It should be about 76 to 78 degrees in his tank at all times. Cold is a big cause of lethargy in fish.
Give him a few days to calm down. Offer some food once or twice a day, take out what he doesn't eat.