All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is not strange that you experience such a state of bewilderment, worry, anxiety and uneasiness, because you have been disobeying Allaah for 8 months without the least sense of regret. You ask only about how to get rid of your fiancé whom you do not love, although you should be asking how to get out of that sinful and heinous relationship. Undoubtedly, disobedience brings anxiety, meanness and weakness along with gloominess of the face and blackness of the heart. There is no way out of this but to sincerely repent. So, turn in repentance to Allaah, give up such an unlawful relationship, regret your past deeds and be determined not to repeat them. You have to remember the suddenness of death, the darkness of the grave and the torture of Hell. You will soon die, with enjoyments fading away and grief lasting. Know that the reward that Allaah Has for you is better and that whoever abandons something unlawful out of fear of Allaah, Allaah Will Compensate him/her in return.
You also have to know that your boyfriend does not fit you as a husband due to his debauchery, dissoluteness as well as declination to wed you. You are settling for such a loss by sinning and disobeying Allaah for the sake of a lewd and dissolute man who does not want you. You are not the first to be fooled in such a way. Many girls followed the fancy of love and therefore they lost their honor and chastity. Then the wolfish men left them victims to sorrows and grief. Sadly enough, there are many immoral persons who frankly state that one of them cannot marry a girl, who allows herself to go out with him. Such men say that they refuse to marry such girls because they do not think they are honorable or chaste.
Moreover, you should not think that debauchery and lewdness is exclusive to fornication or adultery, but it extends to include repeated looking at unlawful things, listening, touching and meeting in seclusion with non-Mahram men. The Prophet, sallallaahu ‘alayhi wa sallam, depicted them all as adultery saying: "Allaah Has Ordained for everyone his share of Zina (adultery/ fornication which s/he cannot avoid. Adultery of the eye is [unlawful] looking; the Zina of the tongue is licentious speech; the soul desires and longs; and the private parts follow them or ward them off." [Al-Bukhari and Muslim]
The wording of another narration reads: "The Zina of the eye is [unlawful] looking; the Zina of the ears is [unlawful] listening; and the Zina of the tongue is [unlawful] speech; the Zina of the hands is [unlawful] striking; the Zina of the legs is [unlawful] walking; the heart yearns and desires; and the genitals may or may not put them into effect." [Muslim]
On the other hand, you do not have to marry a man whom you do not love, and you can end your engagement. But we advise you not to rush into that and to think carefully. If your fiancé is religious and of good character, keep him and do not lose him. Rather, you have to set aside such an illusion and pure fantasy and shun this proscribed relationship. You should know that happiness belongs to Allaah and He Bestows it on whoever obeys His commands and abstains from His forbiddances. We ask Allaah to Make better and reform our lives and those of Muslims in general.
Allaah Knows best.