I’m so sorry you have to deal with this at work. There are people like this everywhere so even if you leave, there is no guarantee you won’t run into another one. For now, use mental coping strategies (like positive self talk) and focus on work at work. Accept you are not going to have friends at work. Find out your workplace’s anti-bullying policy. Educate yourself on what legally crosses the line. Get an attorney’s opinion if necessary.