Grandpa died and idk how to feel anymore

Last night,he got taken by the ambulance since he was so pale and some stuff. He was so sick he couldn’t walk but when we came 4 months ago he could walk. We are back hope for the holidays and we got the call today that my grandpa died and we all were obviously crying but when I first started crying I felt like I was gonna throw up so o stopped. I didn’t sob like my grandma did but I was obviously sad. But then 15 minutes later I stopped and felt normal, then in the car when I was going with my uncles gf somewhere, I was crying again in the car because when he got taken away by the ambulance I saw a tear in his eye so I felt bad. A few hours later we were planning his funeral and everyone was normal and wasn’t crying. I went to go shower and it hit me again. Then an hour later, I went to ask my mom if I can post a picture on Instagram and I started sobbing and couldn’t even ask her but then I stopped, and was normal and then just went back to talking with everyone