We agreed on the division of property, but I’m scared. What to do?translated

Reader question:

Good day! Mom had a one-room apartment for her dad and her two-room apartment, where she lived with her brother. My dad had a one-room apartment. When I was a child, my parents came up to my brother and me and asked who should have what in the future. My brother said he doesn't care. I said, it’s more convenient for me to have two one-room apartments, so my brother needs one two-room apartment. Dad died in 2012, two one-room apartments went to me. I didn’t live with my mother, I moved to my grandfather’s place. Mom died recently. It turns out that she divided the two-room apartment into shares: half for her and half for her brother. Not even 40 days had passed, my brother began to put pressure on me, he signed us up with a notary, and said, you will come with me to write a refusal. He started calling and demanding that I give up my mother’s share, and not always in a sober state. When they buried my mother, right at the grave he started telling me, let’s go, if you refuse. My brother has no children, I have two. My son is his godson. There were rumors that he wanted to transfer the apartment to his cousin’s daughter, his goddaughter. But mom and dad divided it between us so that everything would remain in the family.

My brother initially didn’t talk to me normally, didn’t say that everything would be fine, we’ll go and process it leisurely, as convenient as possible. No,…