I won't be able to get home till the 20th. I'd love to jump on a train right now, but I have to stay for a presentation . I am so scared that she will try something stupid again, even though she's told me before that she's 'stronger'. If anything does happen, I will NEVER forgive myself.
I don't know what to do. Apart from sending messages saying I'll be back soon and trying to reassure her, I don't know what else I can do.
Send her an e-mail back asking what's wrong.
You never know, it might just be one night; like a bad day. I've had nights where I've felt awful; everyone has them.
Maybe tell her you're worried? You don't want her to harm herself and try to hold out if she can.
I'd call her though; if possible.
I hope it gets alright for you.
Also, the phrase "Sorry for writing to you, but it's easier than picking up a knife." makes me think that she wrote to you, so she wouldn't cut.