she doesn't take me seriously

I know this doesn't fit in with the health and life style category, but please hear me out
The past few weeks (2 months)  I have been up to my toes with keeping my room clean and I'm one of those sisters who has to share a room with their sibling, particularly my sister however, I am the only one keeping the room clean, and smelling nice for guests, now that I have a boyfriend, and my sister has a fuck buddy. (I'm 17 and she's 20) 
However ever since I've been cleaning the room like a nut job, she just leaves HER clothes everywhere, She leaves HER STUFF everywhere, and she just disorganized everything I spent an hour organizing. 
I Mean for FUCK SAKES I FOLD AND IRON HER WORK CLOTHES! 
What can I do because it's been cutting into me, I've been stressing over keeping things neat and clean and uncluttered, for my boyfriend who comes over Often, and we just hang out in me and my sisters room. 
Every single time I address it, she just does the opposite. One time It got so dirty I slept on the couch for 3 weeks, and in those three weeks, Garbage was left every where, tissues dirty clothes, an old pizza box, shit from taco bell and it smelled like a rats ass in the room. 
What can I do please help! 
Edit: (She's 20 years old and goes to a community college that's walking distance close)