New York Right of occupancy vs life estate New York who pays the mortgage

my dad passed away a year and a half ago my brother lives downstairs in an illegal apartment in our house so it’s not a true true family. Let’s just say he has a live grandfather and for my He’s 100 years old. We’ve been here for a trying to sort out a contested estate my brother i is remainder man and I am caregiver to my grandfather after being here a year and the house going rears we do not get along. My brother and I I paid all of the bills in the when my brother refused to pay anything, and claiming that my grandfather is a life tenant which we were not aware that it meant that he was responsible for the mortgage the bills as he lives off of a very small check every month is this true is this correct? They said that because there was no language in the trust regarding this exclusive right of occupancy that was granted to my grandfather that this is a life estate, because there was no language in the trust that my grandfather is liable because it defaults to New York ball that if there’s no language, my grandfather‘s liable for the mortgage and utility year while he’s lived here for free and it will inherit the house when we move out which will be soon and the house also is in Forclosure. Please help soon. I need advice and a lawyer referral would be great too.