Are the problems occurring to the family, such as the daughters not marrying, the father's condition changing, and threads appearing from his mouth after he returns from eating, due to an evil eye or sorcery? And what is the ruling on lying to someone and then repenting without informing them?

We do not have what definitively proves the reason for what happened, but ruqyah (Islamic exorcism/healing) is legislated in all circumstances. Lying is one of the most heinous sins, and the Prophet, peace and blessings be upon him, warned against it, saying: "Indeed, those who invent falsehood are those who do not believe." Sincere repentance from lying must be initiated. If the lying resulted in harm, then reconciliation and efforts to solve problems and seek forgiveness from those who were harmed are obligatory. However, if no harm resulted from it, then it is not necessary to inform the one you lied to.