You must try your level best to control your temper and respect your
family. However, you should explain to them in a respectful manner,
that they must stop praticing these customs that go against Islam, for
their own good towards Allah.
Your behavior represents your level of your Iman! It is not an excuse
that you lose your temper as this is a sign of ignorance and lack of
sincerity. Try your level best to stop these whispers of satan and
learn how to control your anger and be diplomatic for the sake of
Allah.