urgent please help

[gizmo101]

my teil gizmo last week had soome very runny watery poo. so i seperated him from his new friend georgia who have only had for about 3 weeks. so he started eating more and singing. but now he is just sitting at the bottom of the cage not chirping or singing or making anynoise whatsoever. i checked on him every half an hour or so and found them the same way . georgia on the food dish and gizmo on the bottom of the cage none of them making a noise. i have seperated him and georgia just 30mins ago and found he was excessivly cleaning around his tail then i lifted his tail to find he has no feathers around his bottom for about 1 to 2 cm . i have no idea whats wrong but could it be tht georgia isnt letting him eat or plucking him underneath his tail around his bottom????

no i dont know how long he has been like this as i was away for 1 day and night. but my mum says he has only been like this from this morning and i know that when i left he was his normal self.

his housing is and outdoor avery and very warm although its more of a very clean shed with perches and so on.
he is always warm and his cage is within the shed type avary and is covered at night or on very cold days and has not had a winter in there at all. again please help because i dont know of any avian vets in wellington newzealand tht have time for emergancy calls or want 200 nzd to see him and as im only 13 i CANNOT afford this