How do I forgive, how can I forget...?

firstly you have every right to be hurt, but what you must realise is this: his ex is still the mother of his children, he loved her once and he probably has nagging doubts as to whether he did the right thing to his children. I really don't think this letter is a slight towards you, but it is trying to convey wanting forgiveness from his children, not his ex as he wouldn't have stood by you for so long would he! He feels guilt about his children he is after all their dad, and has probably missed their prime years. I wouldn't look to much into his words, it is his loyalty to you that is important and he hasn't exactly asked for a divorce in all those years. I would try and put this behind you. He simply probably just didn't know how to get his children on his side, after all if he insulted their mother what do you think they would say, it is a general statement to get his children to love him only.