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.
Know that this kind of relations between a man and a woman is not permissible except after getting married.
As for love and affection, they are of two kinds:
a) Unintentional inclination of the heart towards someone, such as when a man sees a woman and her love captures his heart; this is forgivable in the Sharee'ah. Likewise, when one looks at a woman for the purpose of marriage, and then he begins to love her. There is no harm in such love as long as no forbidden act is committed.
b) One looks intentionally at a non-Mahram woman and then her love enters his heart; this kind of love is forbidden since its means are forbidden. If one loves a girl, the legal way to reach her is to propose to her guardian and offer to marry her. Even after proposing for her, it is not permitted to mix with her, to be alone with her, or to touch her.
Therefore, you should cut all relations with her unless you marry her. Know that Satan is very fond of luring a person towards what is forbidden, so what you are doing may be from the trick of Satan.
Allah Says (what means): {…and follow not the footsteps of Satan. Verily, he is to you an open enemy.} [Quran 2: 168]
Allah knows best.