Those of us with social anxiety usually struggle a great deal with assertiveness. Being assertive is a key part of the "overcoming social anxiety puzzle." In the local therapy group, we have many handouts and behavioral exercises that deal specifically with assertion techniques. Acting assertively and believing in our own worth takes some thought, as we must realize that we, like everyone else, have the right to see ourselves as we really are and to act in a manner consistent with these beliefs.
Sometimes, social anxiety people will say they accept and believe the "Deserving Statements" but they don't FEEL that they are true. So, we must gently consider this. What is rational? What is really true? We must expand our minds and allow for alternative possibilities. Maybe people with social anxiety are just as good as anyone else, and have just as many rights to live a happy life as anyone else? Cognitive understanding is important, but eventually it's important to FEEL at an emotional level like you have the assertion rights you really do have.
You do have these assertion rights, and you are entitled to believe them because they are true. You deserve to accept yourself AND your desire to overcome social anxiety. You deserve to feel OK about yourself. You deserve to calmly stand up for yourself when others make a habit of stepping on your toes. You are in control of your brain, because you can exercise your executive function, and over time your brain must take in everything you are learning, and gradually make changes in a more rational and realistic direction.
You have the right to take your time and take it easy. Don't allow other people, or even yourself, to rush you. You have the right to relax and take your time. No one has the right to rush you or force you to do anything you don't want to do. By learning to act assertively, you will develop a healthier sense of your own worth as a human, and develop more positive emotions and attitudes at the same time.