The potential for external disappointment can be especially devastating when it comes from a loved one. You may initially act with some defiance, but that is masking the kick in the gut you feel. We do not like to let people down.
Internal disappointment can come with a lot of head trash. You may not choose to share your disappointment in yourself with others, but it is hard to escape. You can only do so if you forgive yourself, and as a rule, we tend not to do such a good job with apologies.
The thing is, you have to. What is the alternative? Push it down deep into the recesses of your psyche and ignore it? You cannot sustain that if you want to be healthy and productive.
Instead, embrace disappointment ahead of time.
Imagine your impending action ends up disappointing someone, or yourself. What will happen? What do you imagine the consequences to be? How will you deal with them?
If you did not take the action, would you experience a different kind of disappointment, or would there be relief? By confronting both scenarios, you lessen the emotional strain. You might not have eliminated the fear of disappointment, but you have confronted it, and that puts you in a better position going forward.
Disappointments happen. It is part of living. It is not about the size or severity of the disappointment; it is how quickly you recover from it. If the coffee shop runs out of blueberry muffins, do you let it ruin your day? If you miss a connecting flight, how quickly are you able to act on alternative, albeit inconvenient plans?
You will not fully eliminate disappointment, but your reaction can significantly minimize its influence on you. If you must dwell, don’t dwell on what could go wrong, dwell on reasonable alternatives you can act upon instead.