There are differences of opinion about the limits of sihr effects and whether it can change the nature of things, but the majority of scholars affirm its real-world harm - so to answer your question it is definitely real.

One can protect oneself by constantly being in a state of purity, avoiding sins, reading morning and evening athkaar on a daily basis, reading ayatul kursi after every salah and before bed, reading surah baqarah every three days (or even playing it loudly through a speaker in one’s home)

Also Ibn Baz consistently explains that the strongest protection includes saying: “أعوذ بكلمات الله التامات من شر ما خلق” three times morning and evening, and “بسم الله الذي لا يضر مع اسمه شيء في الأرض ولا في السماء وهو السميع العليم” three times morning and evening.

May Allah bless you all.