I can't stop crying over my baby brother, what should i do?

hello everyone. my baby brother zak was born three months premature in december last year and he died this january. when he was here with us, all the time he was on the ventilator and whenever i went to visit him, i could see him through the ventilator looking at me. all the time i was visiting him i kept thinking "you'll be home soon!" he was doing so well until he passed away (gaining a lot of weight). but the day i found out he died, i have been crying every night for him wishing he was here with us. i really don't know what to do. i don't think i can talk about it to my mum without her crying. the only other person i can talk about stuff to is my nan but i don't think i can because she has been through the same thing (her baby passed away at 2 years seven months). i don't want to forget my baby brother but i really don't know what to do because i haven't been myself since he died. sensible answers please :) x