I'm so sorry you had such a bad experience at the hands of this Christian Counsellor. Finding a person that you can really trust is such an apparently hit and miss affair and, of course, the problem for you now is: how can you ever trust anyone else ever again? I think thats the point that Blackstone is trying to make: not to give up trying just because of one bad experience. I think Chris has it right: always seeing the positive side even if it seems an entirely black episode at the time: God working through but not in the way that we expect or actually wanted.
It's something I've been thinking about quite a lot recently: the huge danger for the Christian is to give advice which doesnt involve any pain for him personally. This to me is a complete misunderstanding of both God and his gospel but it is a route we nearly all follow for a good percentage of the time. I recently wrote to a monastery asking to join (my second one). Like before, they also refused - perhaps because of my BLness (I fessed up)but he did acknowledge that my way to God was indeed through my blness and that I couldnt turn away from this. I thought that was fairly wise.
Our way to God is not through our strengths and successes but through our weaknesses and failings and that goes for Christian counsellors too for sure.