I understand what you are saying about losing time and not wanting anyone to know. I hate it when that happens. It's confusing, embarrassing and scary.
You said you can't stand to be hospitalized. Where I live, you don't go inpatient unless you are a danger to self or others. You sound tormented not suicidal. For what that is worth...
As far as journaling, it helped me to just sit down and write. To not try to sort things out or get them in any order or understand them at all. I just sit down (for me, in front of the computer. I type faster than I write) and let whichever part of me wants to start do the typing. The less I think about it the better. I used a handwritten journal for about the first year. It was amazing to see the differences in my handwriting and language-I later learned that it was different parts writing.
I was encouraged to not sweat about identifying the feeling, just to notice how it felt and write that down. Physically or mentally.
The good thing about journaling is that you can't get it wrong. Just start writing and write until you feel calmer. You are already doing it some, on this site. Maybe start by copying some of what you have said here and then see where that goes?