Can My Property And Home Be Taken From Me?

I'm in a panic. Ive been making payments to my grandfather since 2019 of $800 a month to pay off a piece of property. The total is 55,000. He is in hospice care now, and his Son (executor after my grandfather passes) and his Wife have taken all my grandpa's finances and bills included all his files and paperwork. Included The receipts that show what I've paid thus far and they are being difficult about letting me see the receipts to calculate what Ive paid so far The agreement was i pay him every month until he is paid off, and if he passes before I pay it off the rest of the payments are given to my mom.

I'm afraid his son is going to try to take the property or more money from me. He What Do I need to do or complete to make sure this does not happen? I have a deed of trust between my grandpa and I from a public Notary. I called the county recorder, and they said the property is under my name. What else should I do to make sure his son doesn't do something to take the property from me?