Amethyst, I will offer up prayers for you and of course for your ex hubby to have safe passage into the light. Please do not dwell on the past---leave it there. I know you two were divorced, but you still had a strong bond between you and you shared children together. Anything left unsaid between you--say it now to him and be gentle on yourself. You're a good person, and he wouldn't want you to feel badly.
Know now that he is no longer in pain, and he also wouldn't want his loved ones to be sad about this either.