When someone you love is ill in this way it is natural to feel sorry for them, but they do feed on that, and they feed on the energy they are getting, so the more upset everyone is, the more attention and energy they get.
this....
one of my aunts was like this. when she was happy she was great fun to be around. then she'd be low and a right bitch. she used to try and drown herself in alcohol. my mum found her slumped in the kitchen witha bottle of pills one time. they rushed her to the hospital (5 minutes down the road) to have her stomach pumped. my mum and another sister asked for a doctor to see her with the view to sectioning her. his question was "if i give you another bottle of pills will you take them" "no". with that the doc was happy for her to go on her way. (i'm not having a go at the doctor(s). they see enough loonies and have enough on their plate, and i honestly think that if someone wants to top themselves, they will). a few up and down years and a few smaller incidents inbetween (again, pills, alcohol, wandering off for a night and a day) and following an argument with her fella (was was and is a top bloke who loved her dearly) she jumped from the landing with the belt form her dressing gown tied to the ballustrade and her neck.
my mum and one of her sisters found their little sister hanging, visible from outside hanging, framed in the hallway.
i think now that, despite the upset at the time, that it was for the best.
she finally took the decision to end it, and i, desite her selfishness, respect her decision.
to the OP... i hope things work out for you and her. fingers crossed.