"NO"

That little word but so hard to pronounce ... Many people suffer enormous amounts of stress and anxiety because of saying yes to everything but themselves. They fear looking selfish if they say NO or that they will miss the opportunity train.
Many times we think that by saying "NO" we will hurt and hurt, but no, that depends on the way we say it
Saying "no" does not make you selfish or rigid, in the same way that saying "yes" does not transform you into altruistic or attentive, because you may say yes because of low self-esteem, insecurity, fear of what they will say, need for approval, fear to conflict, etc.
Many times you feel a great obligation to give great explanations for which leads you to say no, but if you want to give your reasons you can do it, of course. What does not make sense is that you make a list of excuses that do not really correspond to the real reasons why you reject that request