Why do I treat every sales slump as proof I'm a failure?

You can already see the trick your mind plays: when you win, it says you got lucky, and when you lose, it says you were exposed. Same person, two different scorekeepers. You have named the pattern, which is a real step. But naming it and being free of it are not the same, and every slump still drags you back into it. That gap between seeing and feeling is normal. The pattern is a groove worn deep by repetition, and slumps are exactly when it reopens. Sales is a numbers game full of things you don't control, yet the old scorekeeper insists every loss is a personal verdict. It is lying, but it is a practiced liar. Next slump, do something concrete: look at the actual numbers over months, not days. Wins and losses both. Let the data argue with the feeling. You will not win the argument once and for all, but each time you check the real record, the fluke-and-verdict story gets a little less convincing.