Glad you are back.
To put answers to your questions in short form, I had to quit drinking to see what any "why" was that I had used as justification/victimhood/pity/"confusion" - and let go of pursuing that "why" because it would take me back to drinking.
It takes time but this stuff can resolve itself and be aided in getting resolved when we learn to focus on what keeps us sober not why we drank.
I hope you go to AA with or without that friend.