I’m sorry you’re experiencing these difficulties, may Allah make it easy for you. You should not give credence to any talk of black magic or evil eye. Instead, recognize that circumstances can sometimes be difficult because of various factors that are not in our control. It is through this that we come to find out how much dependence we have on Allah. Moreover, this will show you how committed you and your fiancé are to each other, which might also point to the state of your future marriage. Take this as a learning opportunity and work hard to remove external influences from your relationship. Engage in prayer and fasting for patience. I am praying for you. If this has become very difficult, you and your fiancé should consider talking to someone who can help you work through these issues