Is what the questioner is suffering from—distress, suffocation, nightmares, and seeing her sisters' children getting terrified when she stays with them—a physical ailment or a spiritual illness that requires legitimate ruqyah?

If the symptoms persist after organic causes have been ruled out, they may be due to sorcery (sihr), spiritual possession (mass), or the evil eye ('ayn). The nightmare described is often "al-jathoom" (sleep paralysis). Ruqyah shari'ah (Islamic exorcism) is recommended, along with maintaining taqwa (piety) towards Allah, frequently engaging in dhikr (remembrance of Allah), reciting Ayatul-Kursi, the Mu'awwidhat (Surahs Al-Falaq and An-Nas), and the morning and evening adhkar. It is also advised to give charitably (sadaqat) often, and to persistently supplicate for well-being and healing, especially during the last third of the night and while prostrating. Additionally, one may seek assistance from a trustworthy Muslim psychiatrist.