(I started this reply the day you posted, and am just now getting it finished - 'I realize you've posted and have had a bad reaction to the Ashwagandha - but I wanted to get this finished.  'Sorry for all my delays)

When I weighed Ashwagandha root powder, it weighed around 7.5 grams per Tablespoon - of course, this weight can vary substantially depending upon the growing & drying conditions (and even how fine/coarse the powder is, and how compressed it is).  I don't have any Kava root powder on hand, so I can't weigh/measure it.

>>>. I've read 3-6 grams is good of ashwagandha a day to heal <<<  That's a typical recommendation...and certainly not a bad place for 'starters' (perhaps 'too much' if you've had a paradoxical reaction in the past).  When it comes to herbs from other countries (particularly one that has been used for centuries), I prefer to depend on the experience of successful practitioners in that country for dosage/usage recommendations. 

I've found similar recommendations (as below)  throughout Aryuvedic practioners over the years.  I never take less than a Tablespoon at a time, and sometimes I take 2T at a time :)

Some Traditional and Non-Traditional Ayurvedic Combinations Using Ashwagandha are as Follows:

General Use: The root is taken in 30 gram dosage for general debility, consumption, mal -nourishment in children, senile debility, rheumatic and arthritic conditions, nervous exhaustion, fatigue, brain-gag, memory weakness, senile dementia, muscular weakness, spermatorrhea and leucorrhea. Normally this can be taken as a powder 10 grams three times daily mixed with warm milk or water, or as a one to 5 alcoholic extract, one or two tablespoonsful three times daily.

Preparations:

Ashwagandha is used in Ayurvedic medicine as a powder, decoction, medicated wine, mixed with clarified butter, combined with honey or sugar syrup or as a medicated oil. The most common form is as an alcoholic extract or capsules, of the powdered root.

Dosage is as follows:

In case you are having ashwagandha powder, then you may take 3 to 6 grams of the powder thrice a day

***

Of course, there are many that would consider this "high dosing"...but it's data like this that causes me to recommend 1-3 Tablespoons daily (7.5 - 22.5 grams daily).

In the "alternative science world" (and from 'capsule sellers'), we commonly see the "3-6 grams daily" recommendations - sometimes even as little as 1 gram daily.   One generally has  to surf/scan through 24-30 'alternative sites' to find even one experienced/traditioner healer & their recommendations.  If you're not comfortable with dosages of that size, start with whatever dosage you are comfortable with, and work up at your own pace/speed if/when you're not getting the benefits we know are there (or back off if it causing an atypical reaction).

Yet,don't imagine for one second that a 1 gram dose (especially in capsules, where the contents may not be released in the intestines where they're mixed/processed with the digestive fluids completely enough to be full assimilated) is going to give you any kind of a true baseline for the correct "dosage amount" for you, or benefits you're getting at that particular 'dose amount'.

>>>I remember the last time I tried ashwagandha it sent me into a total panic attack with just a small ammount.<<<  Again, then start slow/low and work up (or eliminate).

But keep in mind...the "last time" was two weeks ago? two months? two years? And what was your 'benzo status' at that time.  No one (even without benzo issues) is ever in the same state from day to week to month to year...particularly someone with long-term liver issues that has started healing & decongesting their liver (the more congested/compromised the liver, the more reactive we are to everything).

'Sorry you've had such problems with the Ashwagandha :(

Blessings,

Uny