Hi Yaya,
I'd like to check the phrases you talk about to give you an accurate answer.
For the moment. I can tell you that:
llorando is the gerund for 'llorar' (cry), nothing else.
Estoy llorando por ti -->> I'm crying for you,
llanto is a noun, similar to sobbing or weeping.
Ella no pudo aguantar el llanto. -->> She couldn't repress her weeping.
I hope it could help you.
Kind regards,
Christian