What is the religious ruling on my marriage to the girl I desire, despite the refusal of my family and her family, knowing that my family has forced me to sign the marriage contract with another girl from the family?

If the girl is religious and well-mannered, strive to convince your father to agree to her engagement by seeking help from sensible people. If he insists on refusing, then turn away from her and look for another woman of good religious character. If you would be harmed by not marrying her, there is no sin upon you in marrying her without your father's approval, provided her guardian agrees, with the caveat that a suitor is a stranger to his fiancée until the marriage contract is concluded.