Is it permissible to marry someone I love and with whom I have committed a sin, despite my mother's refusal?

You must repent to Allah Almighty with remorse, cease from adultery, and resolve never to return to it, for Allah accepts the repentance of those who repent. The aforementioned young man can propose to you on condition that he also repents. The marriage must be conducted through legitimate and wise means to convince your family, by him proposing to you and enlisting good people to persuade your guardian. A woman is not permitted to marry herself if guardians are present, unless she has no guardians or her guardians prevent her from marrying a suitable man, in which case she should refer her matter to the competent courts. If a guardian rejects someone due to their unsuitability, that is his right. We advise you to persuade your family with kindness, turn to Allah, and cut off your relationship with the young man until the legitimate marriage contract is concluded.