Is the failure to complete the marriage due to the opposition of the suitor's family a matter of divine decree (qadaa’ wa qadar), or a result of the magic that afflicted me previously?

This is from Allah's divine decree and destiny. Neither magic nor anything else can affect anyone except by Allah's permission, in accordance with His saying, the Most High: "And if Allah should touch you with adversity, there is no remover of it except Him; and if He intends for you good, then there is no repeller of His bounty. He causes it to reach whom He wills of His servants. And He is the Forgiving, the Merciful." And His saying: "But they cannot harm anyone thereby except by permission of Allah." The believer believes in divine decree, its good and its evil, and that what befell him was not to miss him, and what missed him was not to befall him. A servant's contentment with Allah's decree is part of their happiness, and their displeasure with it is part of their misery. So there is no need for anxiety or frustration, for what Allah has decreed for you will reach you, and what Allah has chosen is good, as stated in His saying, the Most High: "And perhaps you dislike a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah knows, while you know not." So repent to Allah and do not object to His decree, and ask Him of His bounty.