Building boundaries with people, as someone who is sensitive or an empath, is a slow growth. The bigger work we must do is with the people who trigger us the most. We can't change how someone else reacts to a situation, all we can do is own our own reaction. Learning this process is difficult as healing comes in waves and you often will find yourself revisiting old wounds that you believed to be healed. Learning how to pause being a healer and prioritize yourself can take a lot of practice. Your feelings, your, trauma, and your triggers are valid and it is important to acknowledge that and give yourself grace when these feelings come up.