ANSWER:
If you are financially independent and can support a wife, you can marry her with her father’s consent, otherwise break off all communications with her immediately if you want Allah to forgive you.
If you are ok with angering Allah and ending up in hell, you can maintain your haram relationship with her and Allah will enslave you to her as she would be your means of torment in this life, in addition to the torment that awaits you in your grave and in hellfire, let alone the depression and anxiety she is causing you.