A lot of the advice in this thread is bad.

If you start having a panic attack or severe anxiety, yes, you should drink some alcohol. Drink some beer, and only drink as much as you need until the feeling subsides.

Your dose has probably been accumulating over time. I'd actually recommend you perhaps not start tapering just yet.

You should first get yourself close to baseline. This is what's most important. You're always able to taper; it may take longer the deeper in the hole you get, but it's always possible. The key is to deal with the current situation and stop the constant panic.

Don't order any of these weird online pharmacy things. They're probably not going to help. Only GABAergics can really help (phenibut, benzodiazepines, baclofen, gabapentin, pregabalin, baclofen, alcohol).

I recommend slightly increasing your phenibut dose until you feel somewhat more stable. Until you're not on the verge of panic and horrible anxiety all day. You can also balance it with small amounts of beer when needed.

When you feel you're in a more stable state, it's time to immediately start a rigorous tapering regimen. Decrease very slowly over a period of months, again using small amounts of beer where needed to prevent recurring panic.