((Chopin))

SPECULATION:

You want your T to support you 100% against your Mom.
Even the slightest hesitation on her part makes you think she's siding with Mom, and you hate that. You feel betrayed. And from that point T can do nothing right.

PS: When I feel like that, I say I am paranoid. But my T saw only my anger, not my fear. I had to spell it out.