How can I deal with my parents who are angry about my commitment to the teachings of religion after repentance, and their insistence on actions that violate Sharia, such as shaking hands with women, and their rejection of some manifestations of religiosity, such as growing a beard, while I am keen to honor them?

Paradise is surrounded by hardships, and trials are a divine سنت to distinguish the bad from the good. Islam began strange and will return strange, and one who adheres to the truth in times of strangeness holds a great status. Among the manifestations of this strangeness is the disdainful view towards those who adhere to the Sunnah, such as growing a beard and refraining from shaking hands with non-mahram women. Obedience to parents is obligatory, but it is restricted to what is right and proper, for there is no obedience to a creature in disobedience to the Creator. You must be patient with them, treat them kindly, make frequent supplications for them, and offer advice gently and wisely, so that Allah may open their hearts.