How do I restrict discount codes to single use?

I've been running my Shopify store for two years now, and discount management has become a constant headache. Every time I create a discount code, I'm paranoid that customers will share it widely, potentially cannibalizing my margins. I've tried manual methods like tracking and disabling codes, but it's incredibly time-consuming. My biggest fear is someone finding a public discount code and using it repeatedly, which could significantly impact my profitability. I need a solution that automatically ensures each discount code can only be used once, without me having to manually monitor and manage every single transaction. This isn't just about preventing revenue loss—it's about maintaining the perceived value of my offers and creating a sense of exclusivity for my customers.