((Fuzzybear)), from what you have shared you have experienced toxic people that encouraged you to feel guilty or wrong for saying "no" to them. Toxic people don't like to hear "no" because they prefer to control you. You are allowed to have boundaries, and if other people cannot respect them than you don't want to have them around anyway. You don't have to be mean when you say no either, you can always be a nice person, but a person with boundaries.