In some ways, having them live next door is better. Certainly not easier, but better in the long run. It took a long time for me to see that (my ex and her H (OM) live a few blocks away). I think if they are farther, you don't have to deal with the fall out as much and that just prolongs the dealing.
Sorry to hear of the struggles, but then again - you're lucky for the trouble. It's making you better
Peace, AJ
"Our lives begin to end the day we become silent about things that matter" MLK Put the glass down... "Yesterday I was clever so I wanted to change the world Today I am wise, so I am changing myself."