My curiosity is, have you tried attending an Al-anon meeting. This group is for families and friends of alcoholics.
It is not for their benefit that you go and see what it is about, but for your own.
When we react to other's addictions, we have a trade-off taking place, our power for their aggravation and unhappiness. We lose our own peace of mind in reacting, and we take personal and take home their garbage that they are giving us. Even though you are neighbors, you don't have to do that.
What it sounds like needs to happen is that you need to learn to detach from this person with love. You learn more about this at the meetings. They are very helpful in restoring peace of mind and serenity back to us.
My own life has suffered from reacting to addicts. It caused me serious emotional distress from getting involved in an addicts angry and intentional provocations. They want this of course, because it keeps them from having to look at their own personal CR*P.
You sound like a very caring person who needs a little encouragement to step back from the emotional drama, and experience more serenity.
Good luck in finding your answers, just tried to be helpful.