I have a FBT that is showing signs of dying. He has his face planted on the ground, and not up in the air. He stays in one position and does not move at all unless provoked. He cannot hop properly and has a sort of limp. He is not eating.

This has happened to another FBT i've kept, and died just a day later. What is wrong with this one and what can I do!? He's been perfectly fine, but all the sudden_ poof close to dying. His diet is just crickets and mealworms_ so nothing wrong there. I need some help fast, please respond!!!