Is the money my ex-husband pays to cover my living, housing, and medical expenses, by order of the Canadian court, considered permissible (halal), knowing that I relinquished to him more than I needed?

A man is not obligated to provide maintenance for his divorced wife after the expiration of her iddah (waiting period), unless she is the custodian of their children or breastfeeding them, in which case she is entitled to a fee for custody or breastfeeding. Therefore, it is not permissible for you to take maintenance from your ex-husband after the iddah ends. A court ruling that contradicts Islamic law does not make the forbidden permissible, and what you take would be considered an injustice and an unlawful appropriation of wealth. The proof for this is the saying of the Prophet, peace and blessings be upon him: "I am but a human being, and you bring your disputes to me. It may be that one of you is more eloquent in his argument than another, so I judge in his favor based on what I hear. If I rule in favor of someone, giving him something that rightfully belongs to his brother, let him not take it, for I am only cutting off for him a piece of fire." And his saying: "The wealth of a person is not lawful unless given with his willing consent," and his saying: "Every body that grows from unlawful wealth, the Fire is more befitting for it." Thus, it is obligatory to refrain from taking this money and to return what has been taken, unless your ex-husband willingly agrees to provide maintenance of his own free will.