Is the money I took in excess of my needs forbidden to me, given that I know the correct amount and tried to inform my father, but my mother prevented me?

The mother's act of lying is impermissible, and she must repent. If the father gave the questioner money based on the mother's report, which was contrary to reality, then the excess money is not lawful for him except with the father's consent, due to the Prophet's (peace and blessings of Allah be upon him) saying: "The wealth of a Muslim person is not lawful except with his willing consent," and his saying: "All of a Muslim is sacred to another Muslim: his blood, his wealth, and his honor." He must inform his father of the truth. If he consents, then so be it; otherwise, he must return the excess amount to him.