LPT Request: how do you stop beating yourself up over past social mistakes?

Social mistakes or faux pas that I've made in the past just play over and over in my head. I need them to stop but I don't know how. For example, I was at a party and my friend introduced me to two of her friends. I saw that one of them had crutches leaning against the table. Just to start conversation, I said, "oh what happened?" thinking she broke her foot or something, but the second it came out of my mouth, I realized she was missing her whole leg! Of course I apologized, but I felt horrible. This just keeps replaying in my head along with many other major and minor situations where I've put my foot in my mouth so to speak. How do I stop these moments from driving me crazy?