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 impermissible for the family of your former fiancée to put you under a magic spell. At the same time, you should not accuse them of doing so just because some people told you so. Allaah The Almighty Says (what means): {O you who have believed, if there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance and become, over what you have done, regretful.} [Quran 49:6]
However, even if you are certain that they are trying to put you under a magic spell; you still should not fear that because magic does not affect someone without the permission of Allaah The Almighty. You should take the precautions that protect you from magic.
Allaah Knows best.