FTM: i am currently breastfeeding, how do i know if my baby is full. He has jaundice and was in the…

FTM: i am currently breastfeeding, how do i know if my baby is full. He has jaundice and was in the nicu so they specifically said i had to make sure he was eating right so that his numbers dont go up. Its hard for him to latch on to my nipple so breastfeeding is very hard for me. As a 1st time mom not knowing anything is hard and im scared for my baby. Also they told me he has too pee more but ive cleaned 3 dirty diapers with only poop😓