All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, we ask Allah to forgive and pardon all of us and accept our repentance as He is Oft-forgiving and Most Merciful.
What you are committing with this woman is a great major sin. So, you must avoid it completely and keep yourself away from this woman who invites you to Zina (fornication or adultery). You should admonish her and explain to her the enormity of this sin and that Allah prepared a severe punishment for it. Allah Says (what means): {And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever should do that will meet a penalty. Multiplied for him is the punishment on the Day of Resurrection, and he will abide therein humiliated. Except for those who repent, believe and do righteous work. For them Allah will replace their evil deeds with good. And ever is Allah Forgiving and Merciful.} [25:68-70]
Beware of being in seclusion with this woman or any other non-Mahram woman. Moreover, you must sincerely repent to Allah, seek His Forgiveness continually, and perform good deeds as much as possible. You must keep company with the people of knowledge, righteous persons and stay away from corrupt and bad people.
Finally, we ask Allah to enable you to do good.
Allah knows best.