My kitten about 3-4 month has recently stopped playing since last week just eats and sleeps the whole day?

she has also started pooping and peeing all over the house except her litter box since last week she even peed just near the litter box i have taken care of all the details like dirty litter box i even started putting her in the litter box after few intervals she just jumps off it and what is weird is that she seems to be searching the whole house for something even after eating she goes all around and then finally goes off to sleep wakes up eats searches the whole house and goes off to sleep, what is wrong with her she used to be so playful... plz help