How high of a dose is too high for you?

I just dosed about 6.5 Grams orally of large crystal hydrochloric phenibut. I've been on this drug off and on for 5-6 years. The last time I used any was two months ago and anything under 3.5-4 Grams is and indiscernible from baseline. The first time I used this drug years ago it took 6 hours and three doses to get me high. I took two grams and two and a half hours later I felt sober, another two grams and still nothing so my buddy gave me another dose of 3.5 Grams and then I flew for 16+ hours. I've been prescribed and also abusive of gabapentin and pregabalin for years so my gabapentinoid tolerance is through the roof. It takes +-4800 mg of gabapentin and +-900 mg of pregabalin to achieve analgesic effects(I have chronic pain via Ehlers Danlos syndrome). What's your normal dose? What's your threshold dose and max dose? It takes 3.5-4 G for my threshold and I can dose up to 10-12 G before I start jerking and glitching out or puking and losing consciousness randomly. A few years ago I was dosing 20-25 G at a time every day for like 9 months. I hated it though because I would wake up in withdrawals every morning and would feel like shit every morning for two to three hours waiting on the days dose to kick in. Thankfully I'm not longer doing that.