How to cope with a partner that going through the darkness

Hi everyone,

Not sure if this exactly the right forum but I am looking for help or support.

For the last three weeks I have been on watch with partner, ever since they have said they are wanting to end their life. They have been talking to psychologist and psychiatrist for the last 10 or so years as they have quite a fair bit of trauma and mental health issues to work through, and these professionals also know of them wanting to end their life.

I have been through this journey personally a few times and I know how dark the darkness is. But what I am struggling with is learning how to love the person my partner has become as they go through this. Theythey go through patterns of not wanting to let me go and then pushing me away, they are quick to anger and the sharp word here and there, while being critical of what I do.

I am supporting them in all their progress bit by bit, but it is wearing me down, especially as I pour my love out and know there is no love in return. Which I hope is temporary.

For those who have had partners go through this, how do I manage to stay sane and strong for my partner, while hopefully keeping the love Alice?