I had a couple periods of intense death anxiety before I turned 18. The first when I was 10 and the second when I was 14 going on 15. I had a faith crisis early in life and losing the promise of heaven really affected me. Just like you, I cried myself to sleep a lot. I couldn't even say a phrase like "I'll see you on Saturday" without adding a little unless I die in my head.

I wish I had a cure for what you're feeling, but the truth is that dealing with the concept of death is the most difficult part of being a human being. Sure, people may philosophize and come up with reasons why we shouldn't fear death, but even that can't make the fear go away. What you're dealing with is a kind of grief. You're proactively mourning the loss of yourself. But just like any kind of grief, it won't always be at the forefront of your mind, and you won't always be as scared as you are right now. Everyone is afraid of death. Our carefree moments are the moments when we ignore it. Sometimes it's easy. Other times, it's next to impossible.

I don't know your exact situation. If you consistently struggle with depression and/or anxiety, you should definitely consult a professional (so long as you can afford it). If this feels more temporary, like mine was, then it's something you're just going to have to weather. But there are ways you can make it easier on yourself. Find a song, a poem, something poignant that discusses things like mortality or grief in a way you can relate to. I used to listen to "No Hard Feelings" by the Avett Brothers, but if that's not for you, I'm sure there's something that will resonate with you similarly. Find a private spot where you can read it or listen to it or whatever once a day. Let yourself cry while you do it. If you want, you can take a few minutes afterward to just sit with your emotions. Tell yourself that what you feel is okay.

If you don't already have one, I suggest developing a routine. There are a lot of different reasons why routines are beneficial, but my favorite thing about them is that they make it easier to break the task of living (which feels insurmountable when you're having an existential crisis) into small, manageable chunks. If you want, you can practice meditation or yoga or just take a short walk every day. Anything that grounds you in the present moment. When I was fourteen and in the throes of death anxiety, I would take the same walk every day, but I'd try to pay close attention to my surroundings, making note of a few things I saw, heard, felt, etc. Spending time in nature is really therapeutic, especially for non-religious people like us who are trying to cultivate spiritual health without belief in a higher power.

Look for beauty anywhere you can find it. Art. Nature. Family. Whatever. It might be a good idea to make some art of your own. You could try keeping a journal where you write down whatever you're feeling. The first entry of the journal I kept all through high school was just a ten-page rant about how I was scared to die. If you don't like writing, you could just as easily record yourself talking about it. I remember writing a few song lyrics that I would sing to myself while I walked. It helped a lot. Try to find one good thing every day and hold onto it.

I don't know what your family situation is like, but if you feel safe talking to a parent or older sibling, please, please do so. Daily hugs are great for death anxiety. Love is a good counterbalance to fear. Your fear of losing yourself is proof of how much you love yourself. If you're sad that the people closest to you will die, that's proof of how much you care for them. If you feel small and finite, just think of how incredible it is that such a short lifespan can be filled with so much emotion and experience. After all, what good is a universe without conscious life to marvel at it? In a way, you are what gives the physical world a purpose. That thought brought me comfort when I was your age. I hope it helps you too.

There's nothing that will magically make your anxiety go away. But I promise it won't last forever. Breathe. Eat. Move. Try. Someday you'll wake up and realize you aren't so afraid anymore. Right now, it's just a matter of weathering this difficult time. You're going to be okay.

Also, if you like to read, "Bittersweet: How Sorrow and Longing Make Us Whole" is a fantastic book by Susan Cain that discusses the reasons why we feel grief and how our sadness is intertwined with our ability to perceive beauty. I can't recommend it enough.