Hi SineWave-
My therapist told me this- 'you can have great sex and not necessarily be in a relationship'. Perhaps something like a 'free' or 'friend with rights' or 'one night stands' would work better for you.
My dad is not an alcoholic but he was an airplane pilot that later divorced my mom, remarried and went to live to Indonesia. And Seoul. And several other countries.
He came in and out of my life as he saw fit. Sometimes whole months passed without a word.
Its very sad, the daughter is already learning its ok for partners to leave all the time and to be abandoned. Maybe she thinks or feels its her fault. At least that's how I felt it. I was "not good enough", because if I had been pretty, interesting, thin, he would have stayed. This is very unhealthy and at age 29 I am STILL working through the anger and sadness of these feelings that come very naturally.
From my humble point of view it sounds as if you'd be happier single and the most compassionate thing for everyone involved is to remove yourself from their lives, if you are not going to commit. Just my 2 cents.
As others have said, as long as you are honest with yourself, making tough decisions is slightly easier... at least that is what has happened to me. All the best in your recovery!