Ganie- you did the correct, responsible, humane thing by nuetering your pet!!!!! Karamel will recover, and be good as new, just you wait. While I don't know if it is "true" that cats gain weight after nuetering, I do know they pick up weight as they age, and lose that kitten energy. So, keep him active with play things!! And as suggested by Jenluckenbach, a 'wife' would be just perfect for him now!!! Keep us posted, but I am sure he will be just fine shortly.