Перевод - Русский-Английский - жизнь прекрасна, но мне сегодня немного грустно,...

It should be: "...but today I feel a bit sad, probably because sometimes I(t) feel(s) like crying."

not crying, but want to cry

I would I agree with "I feel like crying" or "it feels like crying" as alternatives to "one feels like crying", which is a more general interpretation of the sense meaning that "people sometimes just feel like crying" and not particularly referring to the person. In a language, there are usually several ways to say the same thing. However, "want to cry" is definitely a wrong translation. I would not agree that my translation is wrong and is to be rejected.

Hi boriva,
I agree with you. I'm sorry, but I guess this translation was rejected by mistake. It happens. I'll undo the evaluation and accept it right away.

@lilian canale
Thank you! I would put the alternative expressions provided by ViaLuminosa in the comments field of the translation, to give more options to the user who requested the translation.