What should I do to avoid the sin of usury, knowing that I bought a house through an interest-based bank loan and cannot pay the full amount at once?

Borrowing with usury is forbidden. However, if you entered into the transaction unaware of its prohibition, we hope there is no sin upon you, based on the Almighty's saying: "So whoever receives an admonition from his Lord and stops, then he will have what has passed, and his affair is entrusted to Allah." And His saying: "And there is no blame upon you for that in which you have erred, but [only for] what your hearts intended. And ever is Allah Forgiving and Merciful." You must repay the principal amount of the loan without the usurious increase if possible. If this is not feasible, then there is no blame upon you in that.