It is so nice to hear that you raised Beep from birth and it sounds like you have done a great job considering he is now 14! When it comes to aging sheep and there life expectancy, because the majority of sheep are production animals, they tend to be removed from flocks before they reach their natural life expectancy. However for sheep that can age gracefully, the average life expectancy would be between 10 and 15 years old. I would be asking a vet to take a look at Beep, and give him a check over. They will be able to provide advice on whether the signs he is showing are down to age alone, or if not can let you know what kind of treatment he needs to feel more comfortable.