The problem with therapists is that they're people. And man, do people suck. Trouble is, not being a person is pretty dang hard. In the various times I've tried it, or had it mandated, it's never been completely useless. Certain episodes, I would even say helpful. Not worth sticking with, though But on the other hand, I'm still fucked up so who am I to say.
On moving past anger specifically, the worst part is when you feel a flare up coming on, and there's some corner of your mind that's wants to let it ride, thinking it's going to be just like old times... but you know it never can be anymore, 'cause some jerkwad told you exactly how the magic trick works.