My grandfather passed away this morning

I don't know how, I haven't got the details yet, but he has had Parkinson's for at least 10 years I think. Last time I saw him was July 17th, his birthday. My parents, sister, and myself went over and surprised him. He was napping when we got there because he had taken a sleeping pill the night before and it didn't wear off quite yet because he hadn't drank much yet that day. We walked into the living room and started singing happy birthday on 3. He woke up with the most surprised and happy face/biggest smile I've seen in a really long time. Im remember him saying "I'll get better" and that just about broke all of our hearts because we knew he only had a couple of years left(or so we thought) I'm happy my last moments with his was that.

When something happens and I'm anxious, upset, mad, or really any negative emotions I get really shaky and a little twitchy. That's how I am right now and I'm kind of glad because other wise I wouldn't know how I'm feeling right now. I got the news less than 15 minutes ago and I was in the middle of cooking french toast. I didn't cry or have any emotion. My mind went quiet and my face has been blank since. I don't mean to repress anything. I wasn't very close to him, but within the last 3 years I definitely did become a bit closer with him. He was hard to understand so we didn't talk much when I did see him maybe 6 or so times a year.

I'm worried for when my parents and sister get home (sister 25 and I'm 21). They're all emotional people, except for my dad, I got his genes. I rarely have breakdowns in front of people and they tell me I need to stop hiding my emotions. It's not my fault though, I just hate crying in front of anyone. I know that they're my family, but still.

I know probably by tonight the news will catch up to me and I'll cry, but for now I don't know what to do. He was the only grandparent I was semi close too and that's because the only one I would've had a good relationship with died when I was 3. I'll miss him, but right now I'm kinda numb.

Any advice how to feel? Or how to deal with this??