For me, distance from T and having L instead, pretty much got rid of my attachment to T. However, after 4, almost 5, years with L and going through a 15 week maternity leave, I'm still attached.

For me, it's a good thing and a bad thing, I guess. Good: we can do more work together because I am able to maintain a connection. Bad because, I don't know, I just thought I could be more independent without her.
We were working on my dependency needs and being able to accept them and voice them. She said that no dependency/too much independence is unhealthy, same with too much dependency. The goal is interdependence. So it's important to develop healthy attachments to safe people. One of my main issues is that I know how to have attachments to therapists/counselors, but not everyday people.
About power: I guess you can say that people who have power over you do so because you gave them that power. On the other hand, I too feel like L has power over me (maybe because I did give her it). The therapeutic relationship is lopsided, imho. She takes little emotional risks, whereas my risks are GREAT. Like this leave of hers. She gets to go off and live her happy fulfilling lofe, while I feel alone and abandoned. Anyways, I know what the power imbalance feels like.