I'm so sorry for your loss. 
It is so hard to get overnight care here for animals that are not standard cats and dogs. Our exotics vet has a number to contact for out-of-hours emergency, but sadly that vet has minimal experience with small animals and is certainly not who I would want to rely on in an emergency. Please don't beat yourself up... unfortunately by the time you find them unresponsive, they are likely in process of passing and there's really not much to do. ((HUGS.))
It is so hard to get overnight care here for animals that are not standard cats and dogs. Our exotics vet has a number to contact for out-of-hours emergency, but sadly that vet has minimal experience with small animals and is certainly not who I would want to rely on in an emergency. Please don't beat yourself up... unfortunately by the time you find them unresponsive, they are likely in process of passing and there's really not much to do. ((HUGS.))