Wow. My heart goes out to you more than ever-- to be that afraid and to write a letter to your children is so sad and so scary...
I have a note in my phone from 2 yrs ago that I wrote after a terrible night with then AH now xAH saying who I hoped the girls could go live with if something happened to me and I keep it as a reminder I guess that I was THAT afraid and that no matter how he acts now, I know how capable he is of terrible stuff...
Not trying to hijack your post-- it just reminded me of that...
I'm glad you found the note before your kids did by the way...