Oh, Ornella! My heart goes out to YOU, too, in the midst of this! It is so painful to see our friends suffer and so agonizing to feel that someone we love is missing out on all the joys that life can bring.
It sounds to me as if you know your friend well and have good insight into what is going on for her. It sounds, too, as if you have already tried the conversations about getting help and she has brushed that away.
I wonder if it would be possible to speak openly to her about your own feelings—to say more or less what you have said here. You might do this in person, or in a note. A note would allow you to express yourself fully and would give her some time to process what you have said. An in-person discussion might feel warmer. So it is tough to say which is best.
Either way, you could tell her that you love her, and care for her, and—from her bitterness and recent complaints, etc.—have guessed that she is feeling very low—and that it worries you to see her this way. You could say that you would like to be there for her, but feel confused about what she needs.
Sadly, I suspect you are right. Any open discussion like this might make her run in the opposite direction.
And yet....at a certain point you must be true to your own feelings. If being with her has become so fraught for you that it is a constant struggle, that is not good. If, as a result of her own need to deny or ignore her deep feelings, you find that you have to hide YOUR real feelings and real self, then perhaps the friendship is no longer a friendship.
Speaking openly with her about how she affects you might be "tough love" but it might also be the wake up call she needs. It is likely that her behaviour has driven many people away from her, and most will not be brave enough to tell her why.
On the other hand, you may feel that your ongoing presence in her life and hers in yours, however unsatisfactory, is important, and in that case you may simply decide to leave things as they are, on the surface. Perhaps that IS what she needs. It is difficult for you, but if you think it is doing her some small good, then perhaps it is the right thing to do. And having made a clear decision, you might feel easier in your own mind about that. If and when she chooses to get help and regain her life, then your relationship may deepen and change for the better; until then, you will continue to check in with her.
But if you think there is any risk she might take her own life, then I would speak up.
I don't know if there is space for you to share your own vulnerabilities and struggles with her, or if you feel comfortable doing so. But if you do, it might help a little bit. Sometimes people who are depressed imagine that others lead perfect lives. Evidence that they do not can make them feel more connected.
Finally, maybe you can tell her about YLF and how much fun it is. Sharing passions is another gift of friendship.
