it might straighten out especially if the fish is still young. I've had one do this before and it was slightly curved up even at 12", and the fish did it when he was about 4". Took about 1 month for mine to start eating, but have heard of others eating sooner. Give him time, and clean water. Let him decide when it's time to eat again though.
about 7-8 inches, seems like he has been this size forever. I dont mind if its up or down, i just want to make sure he lives and has a sustainable life