You have to make up your own mind about what is most important to you. I suspect the truth is that while you say honesty and trust are most important (and I believe you that it is), it is closer to the truth to say that you are frustrated beyond reason at the sitch and WANT to have trust and honesty as much as NEED THEM. Does that make sense?
What I mean is that you are losing patience and I think it is possibly making certain things seem more important than they might otherwise be. I KNOW trust and honesty are important to you but you knew going into this that those were things, along with physical affection, romance and emotional support, that you would NOT get from H until this was over.
I think what you are saying is perfectly fine so long as it's born of true introspection and inspection of your values, after which, you came to the determination that these things being present RIGHT now (trust & honesty) are more important than you marriage in the long term.
My point is that this situation, for better or worse, is temporary. He may leave tomorrow for OW and then it's all moot. He may come back to you, begging forgiveness and then you have a lot to consider, or he may continue to do THIS for the foreseeable future. It's all up to you how long you want to allow this situation to go on.
The last thing I can say, is that yes, detachment IS the only answer and I don't agree that it's dishonest or anything of the sort. What you are saying when you detach is that "I love you but I am not going to allow my emotions or actions to be dictated by YOUR emotions or actions. I still care but I no longer will be affected by you. I will no longer react to you."
In effect, you are cutting the need for trust of him out because he is not someone you are depending on, nor should you be in the sitch you are in. His honesty and trustworthiness are irrelevant because while you would like them to be part of your relationship with him, you accept, and FULLY accept that they are not going to be for the time being. When he decides what he is doing in his life and should that decision include trying to rebuild a M with you, THEN maybe it's time to visit the issues of trust and honesty.
Sorry to ramble and repeat. I think I got it out the way I meant. If not, please ask me to clarify.