My Grandpa Gave Me A Bunch Of Money Before He Passed And Now My Uncles Are Saying I Have To Pay It Back. Do I Have To?

Location: Arizona/ Texas
Hi, I’m gonna try to make this as short as possible. My grandpa was also my father figure. He taught me how to drive, walked me down the aisle at my wedding, etc. I even lived with him and my grandma for many months as a kid and teenager. I moved from Arizona to Texas a couple of years ago, in an apartment. My grandpa wanted to help my husband and I buy a house. He also helped my little sister buy a house. He gave us $10,000 for a down payment. Unfortunately we had too much debt with our car payments, so he gave us another $10,000 and told us we can pay him back just $100 on the 1st of each month with no interest until he passes away and then we’d stop paying. I dismissed him when he told me that because I didn’t want to talk about him passing away. I’m incredibly grateful and I’ve never been so spoiled in my life. I was never expecting him to do something so grand for us. It might also be of importance to note that when we were buying the house, they needed to know where this random money came from, so my grandpa sent them a signed document stating that he gifted us that money. Anyway, this was in July. Fast forward to November, my grandpa gets sick and is told he has 1-1.5 years left. Unfortunately, he left us on Friday, about 6 months after his initial diagnosis. My two uncles went down to AZ to “help” out my mom after my grandpa’s passing. I haven’t seen or spoken to my uncles in about a decade. They never visit, call, nothing. They’re looking over finances and saw a paper that my grandpa wrote on that says “(my name), $100/ month, no interest, $10,000) and they’re insisting I continue making these payments. In the last 10 years, I haven’t gotten a “happy birthday”, “merry Christmas”, “congratulations on the marriage”, nothing. They literally just are communicating with me to pay back the money. They’re very mad that their kids didn’t get any money from my grandpa even though they never call or visit ever. They’re currently selling all of my grandpa’s belongings on fb marketplace as well. My husband and I never signed anything saying we’d pay it back. It was a verbal agreement between my grandpa and I that I’d pay him, and he made it clear that he didn’t expect us to pay that $10,000 back in full. To be clear, if my grandpa were alive, I’d pay him every month without a problem. I don’t want to pay my uncles, quite frankly. But legally, do I have to pay it all back?