Phenibut addiction is a very big problem it would seem. There are many variables at play that make dependence and withdrawal from this drug difficult. In places like Russia, Phenibut is prescribed for anxiety in standard dosages. In the United States, obviously, it's viewed as an Over The Counter "dietary supplement". At this point, I'm sure that the medical (addiction) community is becoming more aware of the drug and how frequently it's being used, but you are unlikely to encounter a typical MD who will understand your dependence, the withdrawal syndrome or its severity.
I have been to detox numerous times and have found that Phenibut is still a relatively obscure substance to them. I had to explain to 3 MD's that it was a Gabapentinoid and once they became aware of its nature, they were in shocked disbelief that it was sold OTC. This is really terrible though, because this lack of knowledge regarding the drug will lead to inadequate treatment for your withdrawal.
I've read that you have Pregabalin (Lyrica) in your toolbox? Well, I've always found the Gabapentinoids to be heavily cross-tolerant with one another. Phenibut is essentially the weakest Gabapentinoid you can acquire while Pregabalin is the most potent. I think you will benefit from other comfort medications, but you need to keep in the forefront of your mind that Pregabalin is cross-tolerant and will be a very important part of your withdrawal.
I will add as a post-script that at the very least, if you end up in the hospital again, do not mention Phenibut. If you truly are having dangerously severe withdrawal symptoms, you will probably need to lie to get adequate care. You will be much better off in this scenario to not mention Phenibut and to say that you are heavily addicted to Benzodiazepines, Alcohol and hell, tell em you take Phenobarbital (Luminal) occasionally.