ooops...fed my ACF minnows..now what?

[nyfroggy]

we have a 6 month old ACF that we've had since he's an embryo, from one of those frog hatchery kits you order from science catalogs. he's been doing ok up until recently, we were feeding him the frog pellets the kit came with but we started running low so we went to the local petshop and asked the guy what to feed him. we came home with some other pellets (that he wont eat) and some small fish that the guy said he could eat. Froggypants (my kid named him) loved the fish, ate two last week and another one a couple of days ago. then he started to shed, which in and of itself didnt worry me, and then he stopped eating (odd because he loves to eat. always.) and he's less active than usual. and the scary thing, his arms and legs have turned pale. so we got worried and Ive been doing some googling, and yeah, now I know PetStoreGuy sold us minnows and that's no good.
so is there anything to be done for him now? how bad exactly is this?
thanks in advance for any advice