All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Indeed, you did well by being keen on not committing what is forbidden in the Sharee’ah with that man whom you love. Indeed, what is required from a woman who loves a man is to fear Allaah and not speak to him without a need, or look at him in a forbidden manner, or be in seclusion with him, and the like.
The Sunnah clarified that marriage is the best solution for those who love each other. Ibn ‘Abbaas narrated that the Prophet said: "The best solution for those who love each other is to marry.” [Ibn Maajah]
On the other hand, a guardian is not permitted to prevent a girl (under his guardianship) from marrying a competent and suitable man without a sound reason as we clarified in Fatwa 91991. Of course, marrying a man who is already married is not a deficiency for rejecting him.
Therefore, we advise you to try to convince your family and especially your parents to accept that you marry that man. First of all, you should seek the help of Allaah, then you may seek the help of whomever you think may influence them. Then, if they accept this marriage, praise be to Allaah, and this is what is required, and if they insist on refusing, you may marry [that man] without their consent.
It should be mentioned that the consent of the guardian is a condition for the validity of the marriage contract according to the most preponderant opinion of the jurists . So, it is not permissible for a woman to marry without a guardian. In case her guardian prevents her from marrying without a sound reason, then she may take the case to an Islamic court so that the judge marries her off or that he appoints someone else to marry her off. For more benefit on the conditions of marriage, please refer to Fatwa 83629.
However, if marriage is not facilitated with that man, then you should endeavor not to be attached to him, and ask Allaah to bless you with a better husband. As for being attached to that man, then this can be easily cured as clarified in Fatwa 84544.
Allaah Knows best.