I am sorry, that must be difficult to watch happen. Unfortunately, I don't think either can be much help to anyone while they are in that state. Just remember that you are not defined by them. They may have been part of your life at some time but who you are and who you become is up to you. I hope writing your letter has brought you some peace of mind. Know that there are people here who care about you and understand that what you are feeling is real and very raw. You have a right to these feelings, because they are yours.