There have been many good things said already......I'll repeat this, you are not an idiot. But I understand why you feel that way! I have felt that way.....getting so quickly attached to T, trusting her more than was comfortable (is yet comfortable) for me, telling her all these deep, dark things I have never told another person ever.....not knowing if I should safely trust her or not. Thinking I was silly and stupid to think I should, when she might not be worth it.....
Heck, I was mad last week, thinking, look, I trusted, I was honest, and see what happened? She hurt me just as others have hurt me.......And yet I see that it isn't the same, it wasn't just as others have hurt me, because there was genuine care in it; and even in the midst of trust being shaken, she proved she's worthy of it.
Yes, my relationship with T is helping me see unhealthy patterns in my relationships in RL and in myself, but my relationship with her is what is helping break those unhealthy patterns so that I learn healthy ones!
Doing emotional work hurts, healing hurts, and hurts makes us pissed off! So your emotions are normal and reasonable as part of the process, I'd say!