If she is your friend you should be able to actually talk to her, be honest tell her how much you value the friendship, tell her what it's doing to you, she may just see that your wanting her to get some help is coming from a place of love, wouldn't you want the same treatment if you were doing those things? You can't make her...but you can express your concern, in the end you really do have to look after yourself first if it is causing you pain i would say stop doing it just like if you were sticking your finger in a light socket..i would tell you stop doing it...whether or not you choose to is up to you but sometimes you got to let people do things and wash your hands of it because there isn't anything you can do. Maybe you will get lucky and after a talk she will make real changes and you guys can continue with the friendship but not talking about it never allows for that to happen...so take a chance imo..best of luck with whatever you decide