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.
It is forbidden for Muslims to have boyfriends or girlfriends. In fact, males should not befriend females. Islam forbids all personal relations between non-Mahram males and females except through marriage.
So, repent to Allah from the relations you had with this non-Mahram woman.
Know also that the sin becomes greater if this woman is married as having illicit relations with her apart from its being a major sin can drive her to disrespect and disdain her husband.
The Prophet said: “He is not one of us (Muslims) the man who spoils the relationship between a husband and his wife.” [Ahmad and Abu Daawood]
On the other hand, her not being interested in her husband is none of your business. It is a private thing.
We conclude that it is unlawful for you to continue your contacts with this lady and you must sever all your relations with her and return to Allah begging Him for Forgiveness.
Finally, know that whoever leaves something for the sake of Allah, Allah compensates him with something better.
Allah Says (what means): {…And whosoever fears Allah and keeps his duty to Him, He will make a way out for him.} [Quran 65:2]
Allah knows best.