Why am I feeling like I am?

I am sorry for you loss. Do not fret about tears, you body is tired and in shock

It takes three days for it to sink in.

Right now, you're probably a bit numb and a bit raw. I remember after my grandma passed away after a long and arduous illness, my dad was worried because my mom wasn't crying for her mother's death. I walked into the house a day later and the floodgates opened. This is a time to be kind to yourself. Don't worry about doing grief "right". There is no right. I'm so sorry for your loss.