It's really up to you and your doctor within...I doubt that there's a "right" choice.
If I'd shared what you did above, I'd probably decide to leave the Valium where it is (or make very small cuts once a month, or something like that), and start cutting the HC more aggressively.
I'd likely work on getting the two fairy equal (as far as mg/day) and make a decision on how to continue based mostly on what's easiest to tolerate.
Good for you for hangin' in there and getting so much accomplished!