Focus on who you have and who you are. Having a good support system of friends or other family members makes cutting ties easier. Maintaining your values is a part of who you are. Knowing who you are, what you stand for, and who supports you is your North Star, your compass.
Don’t pretend everything is okay. Don’t minimize your thoughts and feelings by pretending everything is ok. When applicable, talk to other family members about your situation. Let them know you will be avoiding contact with this person. Briefly explain why, and don’t back down.