What is the way to deal with the family's repeated rejection of the proposal for the girl the young man desires, and their insistence on his marriage to his cousin, and can the resulting psychological struggle and overthinking be treated?

Parents have a great right over their children, even if they wrong them or treat them badly, and their obedience in what is good does not cease. Children are not obligated to obey their parents in marrying someone they do not desire, and this is not considered disobedience. If a son needs to marry and has no money, and the father is wealthy, some scholars have held that it is obligatory for the father to marry off his son. The son should discuss with his parents with politeness and gentleness, seek help from Allah Almighty, and supplicate frequently. There is no objection to consulting psychiatric medicine and taking appropriate medications.