A: I am so sorry that this happened. Please don’t do anything to hurt yourself, there has been enough of that already! Your reaction is perfectly normal. You lived through a very traumatic experience and you should be feeling exactly the way you are feeling.
I’m sure you have heard of Post-Traumatic Stress Disorder (PTSD) in relation to soldiers, natural disasters, abuse, etc. There is a version of it that can begin almost immediately after a trauma, called Acute Stress Disorder. You can develop this disorder by witnessing a traumatic event or even just learning about it happening to someone close to you. There are too many symptoms to list here, but the ones you mentioned are included: feeling on edge, startling easily and feeling depressed. Some other common ones are nightmares, intrusive thoughts and memories, sleep problems and feeling like things aren’t real.
Please talk to your parents about how you are feeling and ask them to take you to a therapist now. You shouldn’t have to go through this alone. Your friend will be getting some help at the hospital. You don’t have to hurt yourself to get help too, just ask. If you are still feeling suicidal please call a Crisis Hotline immediately. You can and will get through this. Give yourself that chance.