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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
A father should not oblige his daughter to marry a person whom she does not like, however, if he forces her to marry him, the marriage is correct according to the view of most scholars .
Nonetheless, some other scholars are of the view that the marriage depends on her consent. This second opinion is the view that we adopt here in Islamweb, and so, she has the right to invalidate the marriage if she did not agree to it.
Even so, if the person who married her is religious and has a good moral conduct, then it is better for the girl to accept what her father had chosen for her as a way of being kind and dutiful to him. Allaah may bless her marriage thanks to her dutifulness to her father. How could she assert that marrying the other person whom she likes is better for her? Many marriages took place according to this kind of love and failed.
Finally, it should be noted that it is not permissible for a woman to have an affectionate relationship with a non-Mahram man outside marriage. Therefore, she is obliged to cut any relationship with that man whom she loves.
For more benefit on how to treat love sickness, please refer to Fatwa 84544.
Allaah Knows best.