A solid suggestion from your POV. Going by HTMA theory, b5 is used to slow down a too fast metabolism. I'm in a failed transition pattern from fast to slow. Though I've left the fast, instead of emerging into slow I'm stuck in a sub-metabolic limbo between them. Thus, for some reason, b5 does not help here.
It was nothing to do with metabolism. You said you were struggling with anxiety and tachycardia. Sounds like it could be adrenalin and hence why you might want to support your adrenals...you won't speed up your metabolism without sorting that out first. Not naturally anyway, you could probably use DNP.