A bit late, but valerian DOES contain a GABAa agonist, possibly more than one, in addition to compounds very similar to valproate, the sodium channel blocker antiseizure drug. IIRC the primary action is GABAa agonism at the loreclezole binding site. Benzos if available, whilst not a fix as such, of course are going to be better than nothing.
Clonidine (or tizanidine or lofexidine if available) will help with the massive sympathetic nervous system overactivation.
Melissa...contains compounds which act as GABA reuptake inhibitors. Not strong, at least not without a strong extract preparation, but better than nothing.
If available, do get phenibut, its a long-acting GABAb agonist, GHB is a short-duration one meaning its difficult to control peak plasma levels and thus withdrawals rebound again and again. Phenibut can at least be used for a proper taper. Phenibut or baclofen will help far better than benzos will, although that isn't to say that benzos should be ignored if available.
For glutamatergic rebound type nastiness, memantine, or low-medium dose NMDA antagonists of other sorts, such as MXE or the PCP analogs, at doses sufficient to cause only mild dissociation, not aiming for a 'hole' will help.
Alcohol could make things worse, as it seems to cause a glutamatergic rebound after use.
Opiates, too, if available, plus cannabinoids, will help.