UPDATE:

I haven’t contacted my sister as mich as I should’ve about this subject due to moving 10+ hrs always from home. That’s no excuse though. It was disappointment. I sent him a message and then talked to her about it. Apparently since she’s come in contact with her money, he’s been blowing up her phone talking trash about our mom and expecting a cut of the money, because he apparently was the one to give to us and not my dead grandmother (eyeroll). I should’ve just left it alone and talked to her about it first. I just thought she’d get mad at me for even attempting, same with my parents. He really broke my heart a little with our messages. Thanks for giving me advice guys! It was much appreciated :,)