OCD or typical existential crisis?

I am 20 years old and I think I had my first existential crisis. A few days ago, the thought of death immediately popped up and I got anxious. I looked all over the internet and Reddit (ik, scholarly research) to find out what really happens after death. I used to assume that we could still watch over our loved ones and that we live on as nature, which isn’t entirely wrong. The energy from our atoms does get transformed to fuel other life sources. But there is no guaranteed heaven or afterlife, no guarantee that we will still exist in conscious, and we never really know what happens. I’ve cried all day and all I did was researching on the topic, looking for a definitive answer. The thought of your brain shutting off, forgetting everything, feeling nothing forever, returning to the state you were in before you were born. I even heard that death is like a heavy calm sleep, which made me afraid to sleep and made me hyper aware of my heart beat. I then lashed out at my parents because I was trying to cope silently but it was getting too painful. It was still out of control. I regret lashing out and I’m thankful they understood but when it gets intense I feel like I can’t hold back. Typically, I am able to cope with thoughts but it’s different because unlike being a predator, pedo or a horrible person, death is the only thing promised to us. I don’t know if this is OCD or just an existential crisis, but it’s an obsessive loop that I’ve spent days in with breaks in between but the thought comes back. :(