PLEASE HELP!!roommate/best friend situation?

I just moved to Houston from Iowa. My best friend was living down there in a 2 bedroom and needed help with rent. I was not happy with where i was living at the time so I decided I needed a change of scenery anyway so I moved all my stuff to Houston. Before I got there we discussed all of these rules we agreed on. Well before I even got there she started letting her soror stay there (supposedly until school starts back in mid August) My things were already down there. It cost me over $1000 to ship my stuff, buy my ticket etc. We also discussed guess sleeping overnight, MY DISLIKE FOR ROACHES(which she said she had none)!, fees, privacy, food, cleanliness etc. Now I'm here.....IT'S ROACH CITY,SHE'S NASTY,I MEAN i feel like i've been scammed. I'm suppose to sign the lease on August 1st (Monday in 2 days) and I want her to sign a contract before I do! I'm going to buy some boric acid and bengal gold spray as well :-(. I'm not a neat freak or anything but I was raised in a household with my uncles who were in the Marines & the Army! My grandma taught me that no womans house should be nasty. I'm not old-fashioned but I feel like no human beings house should be nasty. The other day she went to school, I came out my room and saw like 5 roaches in the kitchen, like i haven't put one thing in the fridge, I also haven't ate real food in days...just chips and water from my luggage! That morning I also saw in the corner of the dining room a birthday cake on the floor..like seriously? A DAMN SHEET CAKE!...SITTING NEXT TO A EMPTY TRASH CAN...so uh yea what should i put in this contract?