Help! Is my cat dying?

My cat, Kristy, is acting strange. She won't eat anything, she won't drink any water, she won't meow, she just keeps laying around and sometimes sleeping sometimes staring at the wall. Occasionally she'll get up and move to another spot. She's my baby and I've had her since I was 3 years old. She's 14 now and I'm 17, we grew up together. I need to know what's going on. I'm so sad, I don't know what to do.