I am so sorry for your loss. I can't imagine your pain. I have suffered loss as well although mine was early (miscarriage and an ectopic together). You did nothing wrong you must know that! Sometimes we never understand why things happen and that is the most frustrating part. It is hard I know to feel alone and that no one cares or relates. Please know that I will be thinking of you on your special day. The reason that you hurt so bad is that you are a fantastic mother to your angel babies and you did your very best!
I really liked the idea of the balloons and letter being released I could see how that might be a great way to honour your children and release all the love and emotion and pain you feel. I will keep you in my prayers and hope that you find some peace within.