To be honest with oneself is the most difficult thing to do, because we have this little design flaw called the ego that has us be able to hide from ourselves and deny some of our own behaviours and our own flaws.
What do they mean by "powerless?" I think that they're saying that they're powerless because their addiction does at least two things to them: it causes them to have a compulsion and it causes them to have an obsession. The compulsion is what we do and the obsession is what we think.