Be sure to get some nightcrawlers. When you do offer the worms be sure to rinse them off in treated water, and offer about three of them clumped together so they look like a larger prey item. I would order some large dubia roaches, and the horn worms might help getting to frog used to eating worm type prey items. Its going to be hard to get your frog to recognize different prey items especially since your frog has been eating mice for so long. Mice are extremely high in fat and are extremely tasty to frogs. I recommend watching ivory reptiles YouTube video tong feeding 101, and start off with the nightcrawlers. Dubia roaches are also a good staple food as long as they are gut loaded properly. Horn worms are another treat food thats high in fat. Really hope everything works out with your frog. Im worried about the winter semi hibernation that some pacman frogs go through each winter.