I think that you either need to bring out some detail on that pitch-black section on the left (as mentioned above), or otherwise darken the lighter area of the left side (see my quick edit below). With almost-equally light areas on both sides of the frame, the eye doesn't really "know" where to enter the frame; when the eye is finally focused on the end of the tunnel, the "stereo effect" created by both sides of the frame being light is a bit mesmerizing (as in confusing).
Like these two, though admittedly, only one was shot with B&W in mind, the other a straight HDR in color and a remake of my original post on this image. Hope I am not hikacking your thread. Only doing so to show s B&W HDR can be done.