How can I A/B test different subject lines email content or discount offers in my recovery emails?

As an e-commerce store owner, I'm constantly battling cart abandonment. My email recovery campaigns feel like they're shooting in the dark. I know different subject lines and offers can dramatically impact open rates and conversions, but I've been manually tracking everything in spreadsheets, which is time-consuming and prone to human error. I want a systematic way to test variations that doesn't require me to become a data scientist overnight. My current challenge is understanding which messaging truly resonates with my audience—is it urgency-driven language, percentage discounts, or time-limited offers? I'm losing potential revenue because I can't quickly identify what motivates my specific customers to complete their purchase. My gut tells me that personalized, strategically timed offers could be the key, but I need a scalable, intelligent approach to testing and implementing these insights.