Don't let certain things slide. You don't have to put up with disrespect. Don't tolerate things that upset you.
Become a fearless human being by accepting the fact that you do not have to deal with the shit people try to shove into your life. You are going to become Fearless in your response to people who think that they can just do whatever they want while being in your life.
Stop asking permission and stop seeking validation to live your life. Be yourself and live your life as you want. Part of living your best life is deciding what opinions you want to accept and which opinions you wish to deny.
You are going to stand up for yourself no matter how uncomfortable the situation because you owe it to yourself.