My guess is that as a child you were made to feel not good enough, worthless, guilty, anxious if you did not achieve what was expected of you. You were given to understand that you let people down. You have internalized those childhood experiences and now there is a more or less automatic connection in your mind of:

do not do what is expected -----> believe you let someone down -----> feel guilty, worthless, anxious

In general, the way to overcome a fear is to expose yourself over and over in a safe way to the feared object/event.

If you are speaking of your parents, helpful steps would be to stick to your guns when, let's say, they want you to study more and you don't want to. I completely acknowledge that it will be painful for you to do that and you will be sorely tempted to do things their way, so as to end the guilt/anxiety/felt worthlessness. Healing will come, though, from safely working through the feelings rather than avoiding or numbing them.

Are you thinking of some specific step that will be disappointing to someone?