I'm sorry you are feeling so depressed right now. I have been there. I know it sucks. There is medication out there to help you get through this tough time in your life. I'm on Lexapro right now, I now have no more anxiety attacks and I can go to sleep at night and not worry that I won't wake up the next morning. I was staying up to all hours of the night cause I was so afraid to go to sleep. Like you, I also worry about death, I'm so scared that I will die and leave my kids with no mommy.
You have to remember that god has a plan for all of us. we may not understand why death happens, and we may not like his decisions, but we will all understand one day.
If you enjoy reading, I highly reccomend a book by James Van praagh, called "Talking to Heaven" This book has really helped me understand somethings. Some people may not believe all the paranormal, but I honesly do. here is his website.
https://store.vanpraagh.com/Categories.bok
good luck to you.