It's absolutely okay to say "no" when you don't feel comfortable or don't have the capacity to do something. Saying "no" is a way to protect yourself and your boundaries, and there is no need to feel guilty or ashamed about it. It's important to remember that you don't owe anyone an explanation, and your "no" is enough.
Saying no is important because it is a way to protect yourself and your time. Saying no allows you to prioritize the things in life that are most important to you, and to create boundaries that help you focus on what matters most. It also helps to protect your mental and emotional energy, so that you can stay focused and productive. Saying no is a way to take control of your life and make sure that you are staying true to your goals and values.
5 ways to say no
Respectfully decline - Let the other person know you are sorry but you are unable to accept the offer.
Offer an alternative - If you cannot accept the offer, suggest an alternative that may work better for you.
Be honest - Explain why you are declining the offer without being too blunt.
Give a reason - Offer a reason for your decision so that the other person understands.
Be firm - Stand your ground and don't be afraid to say no.