Not a doctor, but it could be auto-brewery syndrome [1]. In effect, your gut biome contains fermenting bacteria that ferment sugars and starches into alcohol.

Not a doctor, but it could be auto-brewery syndrome [1]. In effect, your gut biome contains fermenting bacteria that ferment sugars and starches into alcohol. The alcohol might be causing depression, and switching to a diet that avoids fermentable stuff might cause anxiety due to alcohol withdrawal. Again, not a doctor, not a diagnosis, but it might help give you a name that your doctor could look into. 1: https://www.ncbi.nlm.nih.gov/books/NBK513346/ https://www.ncbi.nlm.nih.gov/books/NBK513346/