Is reciting the 3 quls and making dua obligatory before sleep?

Selam new Muslim, So I like to say 3 ajets before sleep Kul huveallahu ehad, Kull euzu bi rabbi and kul euzu rabbi n nas. So I like to use English version of it because I understand it and can better relate to it. So some one was telling me that it has to be in Arabic and I got to blow/whisper in my hands? But I don't have it memorized so I use copy that I hold in my hand. So was I wrong what I was doing can I do it in English and is this is mandatory to do before sleep? thank you

Alaikumassalam wa rahmatullah,

Welcome to Islam and may God make things easy for you. None of that is obligatory. You can read the Arabic transliteration followed by the English instead of saying it from memory, as this is allowed.