Some of us may derive our sense of self by doing things for others. When this becomes extreme and we cannot say “no” for fear of not being liked, we lose our own identity. People pleasing or caretaking are learned behaviors to take care of others’ needs at the expense of their own. The inability to say no may be linked to the self esteem you think you earn by doing things for others. Since your self esteem seems to depend on the things you do for other people, your reluctance to say “no” is understandable. Saying “no” probably makes you feel guilty or selfish because you equate it with disappointing and letting others down. After years of saying “yes” we have taught others that we will “take on” whatever it might be, after all, it is expected that we comply.