I'd want to say...
"Mommy, I'm sorry if you think I failed you and failed life. I'm sorry that i was always a little selfish to my own needs over yours, and i'm sorry you couldnt always love me through it. But, It's ok mommy, i'll always love you enough for both of us.
Marc, Youre my knight in shining armor. You helped me off the ground when i wanted to be buried in it. When i thought i had nothing left to live for, you gave me your hand and held on tight. You loved me more than i could have hoped, and I'm forever grateful. I'm sorry i never said I love you enough, so i hope this time, even tho its the last you'll hear it, you'll know its not the last time i mean it.
Dylan, mommy's little one. You had a brother, you know? you'll have to ask Daddy all about him now. Mommy's sorry she doesnt have a voice to tell you how great he was, or all her hopes for you. I'm sorry if i scold you, I'm sorry if you get in trouble...I'm sorry for anytime you're gonna want a toy i can't buy. But mostly, I'm sorry for all the times you wont hear me say "i love you" because i do pumpkin.
Ej, mommy's angel in heaven. My voice belongs to you now. Use it as a tape player and play it over and over again, so you dont forget what mommy sounds like. Im always thinking of you.
And lastly, everyone who has touched my life, i'm forever grateful."
so now i'm bawling. thats great.