How can I be direct, not rude, while setting boundaries and saying no?
Setting boundaries can be very difficult. Perhaps learning assertive and respectful communication and working on elevating self esteem could be helpful in setting boundaries and getting your point of view, needs, and wants addressed. Addressing what you learned about relationships and yourself in relationships may be helpful.
Boundaries are the rules and expectations for our relationships that help make us feel safe and comfortable. Many people will try to test our boundaries, so learning how to set and reinforce our boundaries is important. Also, knowing that "No" is a full sentence can be helpful. You are not obligated to explain or excuse your boundaries or decisions to keep yourself comfortable and safe. You have the right to say where you choose to spend your time and energy.
Exploring concerns with self esteem can also be helpful. Many times when we put others' needs, wants, and desires before us, we are telling ourselves that everyone else is more important than ourselves. Processing why you may feel this way can help you understand why you do not feel comfortable expressing how you feel.
Some areas to process may include what you were taught about communication, who taught you to communicate this way, who or what situations may have shaped your view of self. Also, is there some anxiety present that makes you worried about speaking your mind? Have you had situations where you were made to feel guilty or hated for telling people how you felt, what you thought, or what you needed?
This does not mean that you cannot take care of others or do for others, but this should be your choice, and not because you feel obligated to do so. This means that you are just as important as everyone else in your life and you are choosing to focus on self care and your mental health before giving of yourself and time to others. Many of us tend to see self care as selfish, but it is simply caring for yourself so that you can help others, if you so choose. If we are not able to do this, it can lead to us not caring for ourselves and being resentful with the people around us.