How to get out of an unhealthy relationship?

I'm in a terribly unhealthy relationship. He lies, has set up online dating accounts, and has a heavy drinking problem. Not to mention dabbles in drugs here and there. These are definitely all deal breakers for me, and I know our relationship is not good. The difficult part is that I made the mistake of inserting myself into his life rather than building my own. I met him 2 weeks after moving across the country. I am somewhat financially dependent on him, he provides me a vehicle and pays the car insurance. I am currently up to my elbows in student loans and can't do much myself. When things are good, they're good. I go well with his family and him with mine. But there is definitely a dark underbelly to the situation. I am having trouble separating from him because he has become my best friend and support after moving. I only have literally 2 or 3 other friends in this whole city and they are past or current coworkers. I can't afford to get my own place so I'm stuck living with my parents in the middle of nowhere with a 40 mile one way commute. I keep telling myself to just wait it out, that this is a temporary situation. But I'm really tired of getting my heart broken and feelings hurt.