Writing things down can help sort out emotions and figure out necessary steps.

If you want my two cents, I say write the letters be as honest and kind as you can, and make the decision whether or not to post them later. Once you re-read them you will be able to decide if they are something your children will benefit from. Additionally it may give you some clarity so you can better explain your condition later.

Something in your post worried me though. Please, don't take offence, this is me concerned about you not criticising: These letters are a just in case right? Not something else?

I hope you are doing ok. Lots of hugs