With time you will adapt to earthquakes and will learn to remain calm in middle of it. Is "normal" in this region and every 4 to 10 years comes severals from 4 to 7 grades. The epicenter was in Granma so there was were more strongest it hit.
So, keep doing, don't think so much about death, is inevitable. Just accept it and try to enjoy, pursuit your dreams and do better everyday.
The thing is that I've never felt something like that in my whole life, and I don't think that's something I want to adapt to 🥲. Also, thinking about how short life is might become in a reminder to not waste our time 🫂.