I'd go ahead and email. You'll be able to get things out and she'll know right where you are emotionally for your session tomorrow. It can't hurt. I would just explain exactly what you're feeling and thinking and she should know where to go from there. I've shared thought of wanting to die (w/o any kind of plan or intention to carry it out) and she said that it's totally normal and even shared a time she had similar thoughts. She said our brains are looking for a solution to the problem, and for me that's what death was to mine- if I die, then I won't have to figure out my schooling/career stuff or deal with the loneliness, etc. I hope things look up for you soon!

[edit] I just wanted to add that I'm talking about wanting to die NOT suicidal plans, of course