What is the ruling on borrowing from the bank with interest for marriage, and what should I do to atone for my sin and have my prayers answered?

While it is good to seek chastity through marriage, resorting to usury to achieve it is a grave mistake and a major sin. Among the means of chastity for a married person are fasting, lowering the gaze, staying away from places of corruption, and associating with righteous people. If you are able to avoid paying usurious interest to the bank, then do so. If you are compelled to pay it, there is no harm if you regret it and repent with sincere repentance. Sincere repentance forgives sins, and the one who repents is beloved by Allah.