I've seen cases of benzo/z-drug withdrawal (after a short 1-2 years of daily use) requiring 3 months to even notice relief from the side effects of the withdrawal (most notably, horrible insomnia). And then another 6-12 months of abstinence to reach a place where the withdrawal effects are no longer top of mind, or subtly present but not overwhelming.
If you were on benzo/z-drug for very many consecutive years (even with short tolerance breaks), especially if those years were before age 25, it's very possible that your brain has never had a chance to function in the way a "normal" (non-altered) brain functions that hasn't been exposed to long term benzo/z-drug therapy.
The scary part about benzo/z-drugs is that they can, over time, change the structure and chemistry of your brain through upregulation and downregulation of receptors in response to the presence of drugs. With benzos in particular, the amount of time it takes to reverse the drug-induced changes seems to be incredibly long (not weeks, barely months, maybe years -- obviously depending on the length of time of initial exposure).
This is all to say that, if indeed you were on ultra long-term benzo/z-drugs for an extended amount of time (2-5+ years), 1 year of abstinence may not be enough to fully recover back to a normal state.
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And I assume you do all the basic sleep hygiene stuff for insomnia: no caffeine (at all, not even in the morning), no stimulants even if prescribed, intense exercise in the morning but not at night, not eating within 3 hours of sleep, no electronics within 2 hours of sleep.
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If you think the first part of my comment is BS, and if you've already done everything in the 2nd part of the comment, I'd highly recommend trying a dramatic diet change: something like going strict vegan and cutting out all processed sugars (and processed foods in general),
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And if that too fails, think deeply about what triggers anxiety / emotional discord in your life, and try to eliminate the source of that completely. This is the hardest advice to follow through with, since for many people it means quitting jobs, ending marriages, disowning family, moving to another country... you get the point.