My friends are dead, and my dad is still a jerk

So two weeks ago yesterday, I (33F) lost quite a few people I knew in a freak accident, and I was really close to a few of them. I am taking it insanely hard but I’ve been trying to stay balanced because I’m also in a full time clinical program getting my masters. Well, the one week anniversary of the accident was Father’s Day and sending my father a text message completely slipped my mind. Like I haven’t really known what day it is lately. So not thinking, I called my mom because I needed someone to talk to after my first full day of my externship at the hospital, and she answered with an attitude. Like I have no idea what the problem was, until she snaps and asks why I didn’t text my father Father’s Day. She’s not the issue, it’s my father. My assumption, since I know him so well, is that he’s been spitting angry since I forgot to text him, definitely decided to cut off the little financial support they provide (which was alllllll his idea two months ago) and probably discussed taking me out of the will. My mom treating me this way is actually quite surprising, especially given that I called her the second I found out about the accident. I feel so betrayed right now, like how could you treat your own child this way in what is arguably the worst time of her life? Has anyone gone through something THIS shocking before? Because I feel like this is a new low, even for him.