Assalamu Alaykum,
If a person sincerely repents to Allah, then every sin is forgiven.
On the authority of Anas (may Allah be pleased with him), who said: I heard the Messenger of Allah (PBUH) say: Allah the Almighty said:
O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you. O son of Adam, were you to come to Me with sins nearly as great as the earth and were you then to face Me, ascribing no partner to Me, I would bring you forgiveness nearly as great at it.
It was related by at-Tirmidhi (also by Ahmad ibn Hanbal). Its chain of authorities is sound.
Riba, (Usury/Interest) is a major sin. Both taking Riba and giving out Riba Loans.
This is because of the injustice it causes by putting people into debt, and by making the rich become more powerful and more wealthy, whilst putting the poor further down.
Allah, most High says in the Quran:
{Those who spend their wealth (in Allâh's Cause) by night and day, in secret and in public, they shall have their reward with their Lord. On them shall be no fear, nor shall they grieve.
Those who eat Ribâ (usury) will not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaitân (Satan) leading him to insanity. That is because they say: "Trading is only like Ribâ (usury)," whereas Allâh has permitted trading and forbidden Ribâ (usury). So whosoever receives an admonition from his Lord and stops eating Ribâ (usury) shall not be punished for the past; his case is for Allâh (to judge); but whoever returns [to Ribâ (usury)], such are the dwellers of the Fire - they will abide therein.
Allâh will destroy Ribâ (usury) and will give increase for Sadaqât (deeds of charity, alms, etc.) And Allâh likes not the disbelievers, sinners
Truly those who believe, and do deeds of righteousness, and perform As-Salât (Iqâmat-as-Salât), and give Zakât, they will have their reward with their Lord. On them shall be no fear, nor shall they grieve
O you who believe! Be afraid of Allâh and give up what remains (due to you) from Ribâ (usury) (from now onward), if you are (really) believers
And if you do not do it, then take a notice of war from Allâh 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).
And if the debtor is in a hard time (has no money), then grant him time till it is easy for him to repay, but if you remit it by way of charity, that is better for you if you did but know
And be afraid of the Day when you shall be brought back to Allâh. Then every person shall be paid what he earned, and they shall not be dealt with unjustly.} (Surah Baqarah 2: 274 - 281)
wasalam
