HELP! Why wont my rabbit eat??!!?

Its been a few days tat my rabbit,Bella, is not eat any thing!!!! She eats peddlets tat are made of timthy hay. We give her baby peeled carrats and cilantro and piesces of peeled apple.! Before she stopped eating she used to it all of this and then one day she just stopped eating... Sometimes we let her go outside in the backyard and let her run around for an hour a day. The backyard used to be dirt but now we put concrete on EVERYTHING and We think she got sick by eating something outside(when there used to be dirt) But we dont know wat happened to her and now when we give her food and she dousnt even look at her food.... we would take her to a vet but without money we cant do ANYTHING!! so please tell me wat you think i should do.. Thanks for taking the time to read this !!