I have a 49-year-old daughter in this same boat, but I no longer blame myself. She was clean for ten years one time and let that go. It's an addiction, and she can't beat it. It breaks my heart, though. I have regrets as a parent, too. I can't take them back or change what's already been done. If I think about it too much I will be miserable. I'm glad you had time with your dad that was somewhat quality before he passed away.