In alanon I learned that having compassion for yourself comes before you can have compassion for others.
It does seem terribly unfair to have alcohol take away someone you love and to be blamed for all that and even more unfair if we think that person was really never there right from the start and that we're not sure why this person sought us out. These are only thoughts in our minds and we can let them go and love ourselves and put our minds elsewhere to the good in us and in our lives.
I am sorry for your pain LI. Take care of yourself and your son. (((HUGS)))