How Keep Yourself Happy

So I met this guy, he's nice and mature, one year younger than me and more into me than I am into him. We had our first date, and it made me so nervous and anxious, that I almost canceled at the last minute...which wouldn't have been nice let's be real.
I want to learn to know him, but just thinking about him and receiving a text from him make me too anxious for what it is... I'm not ready to date I think, do I want to date someone ? How to date someone without feeling like my stomach is torned apart ?

Any advice, anecdote or trick are welcomed ! Thank you !

So like my great grandpa passed away recently and I have no idea how to process it as my family has acted like it's not a big deal. Like it's kind of just tough for me to deal with how he's fine and that nobody brings him up anymore. He's only the second family that I've lost and I couldn't deal with the first one either.