PLEASE HELP!!

I got a kitten 1 week ago today.She was so healthy and happy when we first got her(or so i thought).But after 3 days of having her she starting to sleep all day,not wanting to eat,she has not used the restroom in like 35 hours or so.She wines and wants to be held like a baby all day long.I really do not have the funds to pay for a vet.I dont know what to do we are so scared for her.Has anyone ever had this happen to there precious kitten? Any answers out there please.. Oh i might mention that she eats a normal kitten diet(sad).