All behavior is inspired by avoiding pain or gaining pleasure – and since you usually act on what your brain perceives as the most intense of the two.
So if you think you desire something, but then “sabotage” yourself so you never get what you desire, that means you have mixed feelings about desire (and thus inner conflict): deep down, you feel that desire will give you more pain than pleasure.
In other words, it’s not self-sabotage: it’s your brain protecting you from pain it perceives as stronger than the pleasure you might get from reaching your goal.
Maybe you desire more money, but deep down, you feel money will corrupt you, or make you lose friends, make you feel guilty, or make you lose your drive.
Maybe you have a desire to write or create, but you feel the pain of judgment or rejection is stronger than the pleasure of creating.
Maybe you want to get in shape, but deep down, you feel you’ll give up anyway before reaching any meaningful results, so you’d rather save yourself the pain of future disappointment (a classic self-trust problem).
Maybe you notice a certain destructive pattern in your relationships, but you believe going to therapy and “opening up that can of worms” will be even worse than perpetuating the current situation.
If you keep sabotaging yourself, it might be worth to ask yourself the question: what pain am I avoiding? What am I afraid of? In my imagination, what’s going to happen when I reach my goal; both positive AND negative?
Or even better than just asking: journal about it.