If I doubted that a person made a kind of witchcraft to harm me or if I felt that someone envies me and the results of that are clear. What should I do?
All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
At first, a Muslim should always do his best to think well of people and should not incline to the whispers of the devil, which affect one's judgment, and makes him imagine that every affliction or distress is a sort of witchcraft or envy. This is because a Muslim is protected by Allah's command. He, The Almighty, says (What means):" For him are angels ranged before him and behind him, who guard him by Allah’s command." [Ar-Rad/11].
Yet, the cure of witchcraft and envy can be fulfilled by legal Ruqyah which is based on Quran, such as reciting Al-Korsee verse, Al-Fatiha, concluding verses of Al-Baqarah and the Muawidhatan (i.e. the last two surahs of the Qur'an), in addition to reciting the remembrances of Allah and prophetic invocations: Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:
Jibril (Gabriel) came to the Prophet (PBUH) and said: "O Muhammad (PBUH)! Do you feel sick?" He (PBUH) said, "Yes." Jibril supplicated thus (i.e., he performed Ruqyah): "Bismillahi arqika, min kulli shay'in yu'dhika, min sharri kulli nafsin aw 'ayni hasidi, Allahu yashfika, bismillahi arqika. [With the Name of Allah. I recite over you (to cleanse you) from all that troubles you, and from every harmful mischief and from the evil of the eyes of an envier. Allah will cure you; and with the Name of Allah, I recite over you]." [Muslim 2186]. For more details as regards the legal Ruqyah, kindly refer to [Al-Adkarr] for An-Nawawi(May Allah have mercy on his soul). And Allah The Almighty knows best.