The best thing to do in situations like these is to incessantly dwell on it and kick yourself over it. A good way to make it even better is to imagine the perfect little reality you would have had in this imaginary timeline, even though there's no objective reason as to why you should be led to believe that.
Just send a message to your girl She send me one back But I ain't never read it Cause p***y is only p***y And I get it when I need it.