According to the book Healing with the Medicine of the Prophet (S.A.W) by Imam Ibn Qayyim Al-Jauziyah, The Black Seed is called Habba Sawdaa or Habbat Al-Barakah in Arabic and Shuneiz in Persian
In the Sahihain it is narrated that Abu Hurairah (RA) related from the Propeht (SAW) that he said:
"Use the Black Seed, because it contains a cure for every time of ailment, except for death." (At-Tirmidhu and Ibn Hibban)
They are called nigella seeds (Nigella sativa) in English and Kalonji in Urdu.
Not sure if black caraway is the same thing.
But this alone not cure hemorrhoids. You should start having a high--fibre diet. a sitz bath twice a day will help ease the pain.