You need a way to distract yourself and live in the moment. Keeping your mind and body busy will allow little time to dwell on this. The more you worry the worse it gets. Nobody knows if we have tomorrow, so we have to live for today, and not miss a moment. You don't want to wake up an old person one day and wonder where the years went....you will have worried them away! Worrying about something doesn't change a thing, it only makes us sick and unable to actually live our lives. Hang out with friends, do things you enjoy, just live! Talk to your parents about your depression so you can get some help with that. We hear from a lot of teens so know you're not alone. You are young an need to nip this in the bud now so it doesn't stay with you. Therapy would help you a lot with all of this, and teach you how not to dwell on death. Fear and worry feeds our anxiety, keeping it strong and creating a vicious cycle, stop the fear and worry, and the anxiety cannot exist. We all need help at some time, and this is no different than any other medical condition. Seek help so you can move on. I wish you all the best and take care!
Sorry to hear about your friend. That is young to die of pulmoary embolisms,but like mammo said we never know if we have tomorrow. I too have health anxiety among other things and its very hard when we know or hear of someone dying not too worry about it,but we really do have to try to focus on other things to occupy our minds. Are you on meds or in therapy? If not I would like mammo said talk to your parents and try to find help while you are young. Once you learn some coping skills you should feel much better and they are something we can carry with us forever! I wish you the best of luck in overcoming this!