If you were angry at your t I think a likely reason could be that you feel like by hurting yourself with your t's paperweight, you're getting back at her - not 'punishment' for either of you necessarily, but a kind of 'I've been hurt with your paperweight, are you happy now' sort of thing. Directed venting maybe. I would have no idea though as I don't know about the full situation. Hope you figure it out! ^_^