No matter how well you think you carry yourself, if you do not value yourself it will show. And you'll be treated by what people perceive you as. Know who you are and be confident in it. Know your worth and act on it.
You are allowed to terminate toxic relationships. You are allowed to walk away from people who hurt you. You are allowed to be angry and selfish and unforgiving. You don’t owe anyone an explanation for taking care of yourself.