HELP!

Recently brought a baby budgie (6weeks old). He was great for the first few day, learnt how to perch on finger after 2 days, trilling, singing and exploring cage and house. We had guests over and we thought he would benefit from the visit and let him out... (slaps forehead) what a nightmare it has been afterward!! He has now started to pace back and forth, try and flip the bottom tray/grate off. He then caught himself in between the feed perch and feed tray/bucket screaming so I gently helped him out, he held onto my hand and went limp and struggled to breath he made a sort of chirp but like a broken record being turned down in volume (if that makes sense).. After this ordeal he hasnít stopped pacing, eats ALL day, rarely drinks water and contorts himself into positions on the perch to the point where he just lets himself drop to the floor; thankfully we knew to get a smaller cage when we got him so he can adjust. I thought maybe he can see his shadow on the wall but then we try to do the finger perch again and he loses it! Starts screaming, he isnít scared of fingers/hand but HATES thumbs.. I know weird.. We tried setting him in another room covered and quite to settle him but this hasnít helped.. Put him in the bath with his cage so he wouldnít have anything to hurt himself on but he just isnít going back to the gentle way he was in the beginning.. Any help would help greatly! Thanks xx