I agree to 'follow your intution'. The only thing I can think to add is to possibly consider the HC as a "support" for tapering the Valium. Hence you might want to think about leaving the HC at some level of a therapeutic dose while tapering off the last of the Valium...and then conclude with tapering off the last of the HC.
You're doing great! And I applaud your warrior spirit and your major efforts & accomplishments :)