The next thing I would try is Potassium Chloride powder by Now. It's about 300g per bottle, tastes bad, but the only way I know of to get 4.2g per day. Potassium is important for vocal muscle contraction/relaxation. Then mix 2-3 forms of B1. HCI, Benfotiamine and Sulbutiamine. I use Benfotiamine from Life Extension and Thiamine HCI from GNC. 1 pill should be 300mg+, not 3mg. I take 1200mg B1 daily. Your stack is a good starter. But I would save money over the year to get 1 vitamin per bottle, not multivitamin complexes. The doses are too low that way. The cost sucks, but, that's why most people are vitamin deficient and don't know.