I would write a similar more. Although the way I've done it is to write one to my friend whom I care greatly for, one for my mother, and one for my grandmother. These people are the ones closest to me and I want them to know that nothing is their fault and my passing is mercy for me and should be celebrated.
I personally don't think you should apologize, even though you kind of do. Apologizing implies that you have done something wrong, which you haven't. Your passing was something of beauty. It's not ugly. Also you shouldn't ask for forgiveness, there's nothing wrong with ending something so horrible that it's unbearable. So you have done nothing wrong. Just let everyone know that you love them, that they did right by you, that they should love you no matter how hard it might be.
You are helping yourself, not killing yourself...