How to sort out potental problems with roomate?

i just moved in with my best friend a little over a week ago and theres already problems we moved in to a one bedroom townhouse with a loft i got the loft and she and her bf have the bedroom were supposed to split everything but she likes the ac on full blast all day long i cant afford a 200 dollar bill plus she has 7 animals and my 2 mice she doesnt take care of very well her bf and i walk and feed the dogs cats ferrets and fish she does work over night so i had some compassion for that now shes comming to expect it she came home the other night and i took the dogs on an hour long walk when we got back she had done a bunch of stuff and was cleaning the ferret cage and she got huffy towards her bf and me that it hadnt been done and then she took out the dogs again even though i had just done it i dont mind taking care of the animals for heaven sake its literally my job im a vet tech i just want my best friend to start treating me like she did before we moved in together. just for a little background info to the problem i had never been to her apt before i moved with her as soon as you opened the door to the old place she lived the stench of urine over whelmed you and there was urine and feces everywhere the kitchen smelled like rotten food and every inch was covered in a film even her room and the bathroom were gross i cant live like that i am not on the lease or any paper work so i cant be held accountable so in essence i just need a simple and effective way to stop a problem before they start