It's so hard to be where you are. I feel your pain and I can relate.
For me, ctb feelings do not accumulate over time. They are more like a yes/no question: either I want to ctb or I'm cool to hang out for a while. Avoiding hospitalization would not make them "add up" for me. I don't know if it is like this for you.
You do not have to answer these questions, but they might help us help you: do you suffer with a mental illness? I am bipolar and the feelings you are describing are what I get in what's called a "mixed episode." They are very, very dangerous and suicide happens a lot for patients who have them.
Also, I am guessing you have been hospitalized before and it was not helpful. Are you in a place where you can choose your hospital? You might be able to find a better place this time if you need to go. Have you tried an intensive outpatient program or day treatment? I have found those to be more helpful than inpatient treatment.
Most importantly, do you want to die? Are you ready to exit this life completely? Is it you or just the voices in your head?
I think that's the best place to start. If you're not really ready and wanting to die, it's better to wait, even if the feelings are telling you otherwise.
Hang in there, and keep posting. We're here for you.