Pacman frog Dead

I just found my pacman frog dying in his cage, i made an apointment with the vet but he passed away long before i would have been able to see the doctor. I am not sure what killed him. He didnt eat much but i know this species can go for long periods without eating. he was in a ten gallon tank with a jungle mix substrate, and a large pool of dechlyorinated water to bath in. I misted him and his whole tank with dechlyorinated water several times a day. he doesnt have a heat lamp but it is very warm where i kept him in my room. When i saw he was weak i put in probably a dozen crickets, but i dont think he ate any. it seemsthat the crickets seem to be dying too though, i found several dead crickets, with no visible signs of a cause of death. He was my first frog and this is quite a blow to me, do you think it was my fault?