How do you get over it when other people verbally or physically abuse you?

It sounds as if they are either sadistic and have some mental issues such as personality disorders to allow harm or humiliation to their grandchildren. The way to get over it is to understand what causes such things, and understand that they are living in their own sick world. People with borderline personality disorder, for example, are very destructive to the people whom they should be caring for the most. They are very creative at thinking up new ways of doing harm to others. As a result, they will end hurting themselves the very most because they are driving the people away who should be closest to them. I have such relatives and will never trust them again. That doesn't mean I carry a lot of anger around inside of me. Such anger would only rob me of my time, energy, and emotional well-being. I do set strong boundaries and don't let them come back within those boundaries after they've totally lost my trust. You'll do best to surround yourself with people who know how to love and who will respect you, and devote your energy to making your life a better one.