Praise be to Allah.
We ask Allah to enable you to repent from dealing with riba (interest), because riba is a major sin and dealing in it means that one is subject to a stern warning.
Allah says (interpretation of the meaning):
“O you who believe! Fear Allah and give up what remains (due to you) from riba (from now onwards) if you are (really) believers.
And if you do not do it, then take a notice of war from Allah and His Messenger but if you repent, you shall have your capital sums. Deal not unjustly (by asking more than your capital sums), and you shall not be dealt with unjustly (by receiving less than your capital sums).”
It was narrated that Jabir (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings of Allah be upon him) cursed the one who consumes riba and the one who pays it, the one who writes it down and the two who witness it, and he said: they are all the same. [ Muslim]
Part of repentance is getting rid of the interest that you are paying to the bank. If this interest can be waived in full or in part, then you should hasten to pay the instalments even if it means selling your house. But if you are obliged to pay the interest and you cannot get out of it or reduce it, there is no sin if you make use of the house, either by living in it or by renting it out, etc.
We ask Allah to accept your repentance and help you to do that which He loves and which pleases Him.
And Allah knows best.