tell her she is responsible for her own health issues. and expect backlash. have a plan. tell her your plan...(calling pd for a welfare check etc) stick to your plan. then tell her you feel this isn't the best friendship for you as it is causing damage to YOUR health and tho you are very sorry but you must end it. tactfully put the onus on you (even tho it may not be) then END it. don't ever pick up her phone calls, facebook messages what ever.

maybe not consciously she is playing you for support that has morphed into abuse...even tho I doubt she knows it is abuse. it will just get worse...you are going to get sucked in to a never ending cycle that will just get deeper and deeper and leave you feeling guilty about ending it..because she will kill herself. get out now. take the fall and say it is hurting your health so as not to produce more drama...but give her the steps