Small brother claims I assaulted my father and made a will forcefully

My father was very ill, he suffered from diabetes, hypertension, heart disease and he was a double amputee. I lived with my father for 24 years before his passing in 2018 and I took care of him fully. My father made a will in 2009 on my brother's name and in 2018 my father made a will stating that he gave all his children land and he is leaving the property in my name. He died 2 months after. My brother is claiming that my dad was not in his right frame of mind when he made my will and he is contesting it claiming I abused my father and forced him to make my will. I was the only sibling caring for my handicapped father with help only from my daughters aged 20 and 26 (current ages) while taking care of my father I also had to take care of my younger daughter who is currently 8 years. Two of my daughters were born in my father's house and my first lived there for 24 years. I currently reside in Trinidad (West Indies)