I think I have been "addicted" to people before, although not to the extreme. For me I think I was having a lot of internal pain, anxiety, loneliness, and this person/people could provide me with something like feeling happy/secure, etc, but it was brief and didn't come from within me. I realized after moving away from some of these people, that it was a bit of a crutch for me, and that I wasn't really addressing the fact that deep down I was depressed. In a way, I think this resulted in giving over my power over my own life a little bit. Getting away from this was very painful, and resulted in a bit of a breakdown because I suddenly had to just sit with these terrible moods and really face them. This spurred me into finally getting into treatment and seeing a psychiatrist, though.

On a positive note, all of those relationships are so much healthier now and I don't feel as dependent on them to make me feel happy or secure. I am not sure that was the best way for your T to bring it up, but it definitely is something that I am not surprised your T would want to address, because otherwise you might remain stuck and not progress in therapy. There is no reason to feel bad, though, it probably means you just have some things that need working out in therapy.