DEAR AMY: I had a 10-year marriage and two beautiful children with someone I couldn’t live with, but who has been my best friend ever since. While it didn’t work out, my ex and I have remained solid parents, confidantes, and friends. He has been in a long-term (10-plus years) relationship with a brilliant woman whom I have trusted heart and soul with my children for over 10 years. She and I are truly close friends. Everyone in my life is aware that I have stage-3 blood cancer. Here is my question: If I had to write my funeral plans today, at 59, and I had my ex-husband’s permission, I would li…