Sorry you're having this problem! You aren't alone.
When I switched insurers, loperamide was no longer covered and cost over $100 per bottle. Costco had stopped selling its own formulation in bulk and was now limiting customers to one blister-pack of 36 pills per day. It was cheap but inconvenient. Then, with Covid-19 patients reporting GI symptoms, it went flying off the shelves everywhere anyway.
Eventually we figured out that my insurer, which won't cover loperamide or Lomotil at all, will cover diphenoxylate/atropine (generic Lomotil) at $30 for a 90-day supply.