BubbaWitt
That is the problem with lithiums. You get little, if any, warning that the batteries are going to die. They show P5 until they don’t. It’s a matter of either they have enough power or they don’t, there’s no gradual decline like there is with alkalines and rechargeables.
How many pictures did you get? It’s hard to imagine that it would be enough to deplete a set of batteries, though, even if you got a lot of pictures.
I have had SD cards go bad. The fact that they have worked for x amount of time doesn’t mean that they won’t quit working. However, it also means that the SD card may not be your problem. You didn’t mention the class of the card, but it needs to be class 10.