depends, were they your friend, companion, relative, or other? If a friend stabs you in the back then I say ditch them, ghost them and or call them out on it. If its a companion then dump them quit talking to them and or confront them and tell them how much it affected you. If it's a relative then confront them about what they did and why and tell other family members about it and ask about what you should do to people inside the family. If it is other then I would block their number, take comfort in a friend, and take a while to calm down and take care of yourself.
Explanation:
Sorry that happened to you, I am a stranger so I have no idea what happened or what to tell you to do. This is what I would do in those situations and what I see a lot of others do. Hope you feel better and get back on your feet soon
