What would you do in this situation?

my former roommate says i owe her almost 500 dollars because i only paid half the rent for the last month that i stayed there, and i also did not pay her for the electric bill or the water bill. but the reason why is because before i moved in we agreed that i would stay for 6 months and that my rent would be 500 a month. she said that i did not have to sign a lease. also she said that her cats would not bother me or my pets or other stuff. also she said her landlord said its ok that i have pet snakes in the house. and she said that she will not have dogs in the house. then after i moved in she changed the rent to 600 dollars, and her landlord found out i was living there and said i have to sign a lease for 1 year, and also that snakes are not allowed. plus her cats were tormenting my pets, eating my food, shedding hair on pretty much everything i own etc.. so after about a month she says i need to look for a new place to live. then she got a dog knowing that i am allergic. then later we found out the dog has giardia so i had to take my sugar gliders to the vet to have them checked as well. so i am not paying her any more money, i ended up losing so much money because of her and her b.s. i am pretty sure that she only wanted me to live there for 2 months in the first place she just told me what i wanted to hear to get me to move in for 2 months so that she could have someone to split the rent with until her boyfriend got out of his lease. sooo she will not stop text messaging me calling me ugly and all this stuff, and her brother calls my boyfriend threatening to beat him up, plus she says that she is keepin any of my mail that ends up at her house she will not give it back to the mailman to forward it. what should i do? thanks